Hesiod, Theogony 390 ff (trans. Evelyn-White) (Greek epic C8th or C7th B.C.) :
"The Olympian Lightener [Zeus] called all the deathless gods to  great Olympos, and said that whosoever of the gods would fight with him  against the Titenes, he would not cast him out from his rights, but each  should have the office which he had before amongst the deathless gods;  he said, too, that the god who under Kronos had gone without position or  privilege should under him be raised to these, according to justice."
Hesiod, Theogony 617 ff :
"[Zeus] the son of Kronos and the other deathless gods whom  rich-haired Rhea bare from union with Kronos, brought them [the stormy  Hekatonkheires] up again to the light at Gaia's (Earth's) advising. For  she herself recounted all things to the gods fully, how that with these  they would gain victory and a glorious cause to vaunt themselves. For  the Titan gods and as many as sprang from Kronos [Zeus,  Poseidon and  Haides] had long been fighting together in stubborn war with  heart-grieving toil, the lordly Titenes from high [Mount] Othrys, but  the gods, givers of good, whom rich-haired Rhea bare in union with  Kronos, from Olympos. So they, with bitter wrath, were fighting  continually with one another at that time for ten full years, and the  hard strife had no close or end for either side, and the issue of the  war hung evenly balanced.
But when he had provided those three [the Hekatonkheires] with  all things fitting, nectar and ambrosia which the gods themselves eat,  and when their proud spirit revived within them all after they had fed  on nectar and delicious ambrosia, then it was that the father of men and  gods spoke amongst them : `Hear me, bright children of Gaia and Ouranos  [the Hekatonkheires], that I may say what my heart within me bids. A  long while now have we, who are sprung from Kronos [Zeus, Poseidon,  Haides] and the Titan gods, fought with each other every day to get  victory and to prevail. But do you show your great might and  unconquerable strength, and face the Titenes in bitter strife; for  remember our friendly kindness, and from what sufferings you are come  back to the light from your cruel bondage under misty gloom through our  counsels.'
So he said. And blameless Kottos answered him again : `Divine one, you  speak that which we know well: nay, even of ourselves we know that your  wisdom and understanding is exceeding, and that you became a defender of  the deathless ones from chill doom. And through your devising we are  come back again from the murky gloom and from our merciless bonds,  enjoying what we looked not for, O lord, son of Kronos. And so now with  fixed purpose and deliberate counsel we will aid your power in dreadful  strife and will fight against the Titanes in hard battle.'
So he said: and the gods, givers of good things, applauded when  they heard his word, and their spirit longed for war even more than  before, and they all, both male and female, stirred up hated battle that  day, the Titan gods, and all that were born of Kronos together with  those dread, mighty ones of overwhelming strength whom Zeus brought up  to the light from Erebos beneath the earth. An hundred arms sprang from  the shoulders of all alike, and each had fifty heads growing upon his  shoulders upon stout limbs. These, then, stood against the Titanes in  grim strife, holding huge rocks in their strong hands. And on the other  part the Titanes eagerly strengthened their ranks, and both sides at one  time showed the work of their hands and their might. The boundless sea  rang terribly around, and the earth crashed loudly: wide Heaven was  shaken and groaned, and high Olympos reeled from its foundation u nder  the charge of the undying gods, and a heavy quaking reached dim Tartaros  and the deep sound of their feet in the fearful onset and of their hard  missiles. So, then, they launched their grievous shafts upon one  another, and the cry of both armies as they shouted reached to starry  heaven; and they met together with a great battle-cry.
Then Zeus no longer held back his might; but straight his heart  was filled with fury and he showed forth all his strength. From Heaven  and from Olympos he came forthwith, hurling his lightning: the bold flew  thick and fast from his strong hand together with thunder and  lightning, whirling an awesome flame.The life-giving earth crashed  around in burning, and the vast wood crackled loud with fire all  about.All the land seethed, and Okeanos' streams and the unfruitful sea.  The hot vapour lapped round the Titenes Khthonios (Earthly): flame  unspeakable rose to the bright upper air (aither): the flashing glare of  the thunder-stone and lightning blinded their eyes for all that there  were strong. Astounding heat seized air (khaos): and to see with eyes  and to hear the sound with ears it seemed even as if Earth (Gaia) and  wide Heaven (Ouranos) above came together; for such a mighty crash would  have arisen if Earth (Gaia) were being hurled to ruin, and Heaven  (Ouranos) from on high were hurling her down; so great a crash was there  while the gods were meeting together in strife. Also the winds brought  rumbling earthquake and duststorm, thunder and lightning and the lurid  thunderbolt, which are the shafts of great Zeus, and carried the  clangour and the warcry into the midst of the two hosts. An horrible  uproar of terrible strife arose: mighty deeds were shown and the battle  inclined. But until then, they kept at one another and fought  continually in cruel war.
And amongst the foremost Kottos and Briareos and Gyes insatiate  for war raised fierce fighting : three hundred rocks, one upon another,  they launched from their strong hands and overshadowed the Titanes with  their missiles, and buried them beneath the wide-pathed earth, and bound  them in bitter chains when they had conquered them by their strength  for all their great spirit, as far beneath the earth to Tartaros . . .  There by the counsel of Zeus who drives the clouds the Titan gods are  hidden under misty gloom, in a dank place where are the ends of the huge  earth. And they may not go out; for Poseidon fixed gates of bronze upon  it, and a wall runs all round it on every side.There [the  Hekatonkheires] Gyes and Kottos and great-souled Obriareus live, trusty  warders of Zeus who holds the aegis . . .         But when Zeus had driven the Titanes from heaven [then Gaia bore  the monstrous giant Typhoeus to oppose Zeus]."
 Hesiod, Theogony 881 ff : 
"But when the blessed gods had finished their toil, and settled  by force their struggle for honours with the Titenes, they pressed  far-seeing Zeus Olympios to reign and to rule over them, by Gaia's  (Earth's) prompting. So he divided their privileges amongst them."
Hesiod, Theogony 421 ff : 
"For as many as were born of Ouranos and Gaia [the Titanes]  amongst all these she [Hekate] has her due portion. The son of Kronos  [Zeus] did her no wrong nor took anything away of all that was her  portion among the former Titan gods : but she holds, as the division was  at the first from the beginning, privilege both in earth, and in  heaven, and in sea."
Eumelus or Arctinus, Titanomachia (lost poem) (Greek epic C8th B.C.) :
Next to Hesiod, the  oldest poem describing the Titan-War was the Titanomachia,  a lost Homeric epic attributed to the poet Eumelus of Corinth or  Arctinus or Miletus. The content of the work is largely unknown.
        Eumelus or Arctinus,  Titanomachia Fragment 1 (from Photius, Epitome of the Chrestomathy of  Proclus) (trans. Evelyn-White) (Greek epic C8th B.C.) :
"The Epic Cycle begins with the fabled union of Ouranos (Heaven) and Gaia (Earth),          by which they make three Hekatonkheiroi (hundred-handed) sons and three Kyklopes        to be born to him."
          Eumelus or Arctinus, Titanomachia Fragment 3 (from Scholiast on Apollonius Rhodius, Argonautica 1. 1165) : 
"Eumelos says that Aigaion was the son of Gaia (Earth) and Pontos (Sea) and,          having his dwelling in the sea, was an ally of the Titanes."
Eumelus or Arctinus, Titanomachia Fragment 5 (from Athenaeus 1. 22c) :
"Eumelos [in the Titanomakhia] somewhere introduces Zeus dancing : he says--`In the midst of them danced the Father of men and gods.'"
[N.B. Presumably this is the war-dance of the Kouretes.]
Anacreon, Fragment  505d (from Fulgentius, Mythologies) (trans. Campbell, Vol. Greek Lyric II) (Greek lyric C6th B.C.) :
"According to Anakreon . . . when Zeus was beginning warfare  against the Titani, i.e. the sons of Titan (Titanas), brother of Kronos  (Saturn), and had sacrificed to Ouranos (Heaven), he saw an eagle fly  nearby as a favourable omen for victory. In return for this happy omen,  and particularly because it was indeed followed by victory, he put a  golden eagle on his war standards and dedicated it as a protection for  his valour."
Aeschylus, Prometheus Bound 200 ff (trans. Weir Smyth) (Greek tragedy C5th B.C.) :
"When first the heavenly powers (daimones) [the Titanes  and the Olympian gods] were moved to wrath, and mutual dissension was  stirred up among them--some bent on casting Kronos from his seat so  Zeus, in truth, might reign; others, eager for the contrary end, that  Zeus might never win mastery over the gods--it was then that I [the  Titan Prometheus, although advising them for the best, was unable to  persuade the Titanes, children of Ouranos (Heaven) and Khthon (Earth);  but they, disdaining counsels of craft, in the pride of their strength  thought to gain the mastery without a struggle and by force. Often my  mother Themis, or Gaia (Earth) (though one form, she had many names),  had foretold to me the way in which the future was fated to come to  pass. That it was not by brute strength nor through violence, but by  guile that those who should gain the upper hand were destined to  prevail. And though I argued all this to them, they did not pay any  attention to my words. With all that before me, it seemed best that,  joining with my mother, I should place myself, a welcome volunteer, on  the side of Zeus; and it is by reason of my counsel that the cavernous  gloom (melanbathês) of Tartaros now hides ancient (palaigenês)  Kronos and his allies [the Titanes] within it. Thus I helped the tyrant  of the gods [Zeus] . . . As soon as he had seated himself upon his  father's throne, he immediately assigned to the deities their several  privileges and apportioned to them their proper powers."
Pseudo-Apollodorus, Bibliotheca 1. 6 - 7 (trans. Aldrich) (Greek mythographer C2nd A.D.) :
"When Zeus was grown, he engaged Okeanos’ daughter Metis as a  colleague. She gave Kronos a drug, by which he was forced to vomit forth  first the stone and then the children he had swallowed. With them Zeus  fought a war against Kronos and the Titanes. After ten years of fighting  Ge (Earth) prophesied a victory for Zeus if he were to secure the  prisoners down in Tartaros as his allies [the Kyklopes and  Hekatonkheires]. He thereupon slew their jail-keeper Kampe, and freed  them from their bonds. In return the Kyklopes gave Zeus thunder,  lightning, and a thunderbolt, as well as a helmet for Plouton [Haides]  and a trident for Poseidon. Armed with these the three gods overpowered  the Titanes, confined them in Tartaros, and put the Hekatonkheires in  charge of guarding them. The gods then drew lots for a share of the  rule. Zeus won the lordship of the sky, Poseidon that of the sea, and  Plouton the rule of Haides’ realm."
Pseudo-Apollodorus, Bibliotheca 1. 34  :
"Now because of her anger over the Titanes, Ge (Earth) gave birth to the Gigantes, Ouranos (Sky) was the father."
Apollonius Rhodius, Argonautica 2. 1232 ff (trans. Rieu) (Greek epic C3rd B.C.) :
"Kronos son of Ouranos . . . in the days when he ruled the Titanes in Olympos and Zeus was still a child."
Apollonius Rhodius, Argonautica 1. 498 ff : 
"He [Orpheus] sang of . . . How, in the beginning, Ophion  [Ouranos?] and Eurynome [Gaia?], daughter of Okeanos, governed the world  from snow-clad Olympos; how they were forcibly supplanted, Ophion by  Kronos, Eurynome by Rhea; of their fall into the waters of Okeanos; and  how their successors ruled the happy Titan gods when Zeus in his  Diktaian cave was still a child, with childish thoughts, before the  earthborn Kyklopes had given him the bolt, the thunder and lightning  that form his glorious armament today." [N.B. Ophion and Eurynome might  be Ouranos and Gaia or Okeanos and Tethys.] 
Callimachus, Hymn 1 to Zeus  (trans. Mair) (Greek poet C3rd B.C.) :
"Zeus . . . dealer of justice to the Ouranides (sons of Ouranos)."
Callimachus,  Fragment 54 (trans. Trypanis) (Greek poet C3rd B.C.) :
"Mekone (Poppy), seat of the Blessed, where first the gods cast  lots and apportioned their honours after the war with the Gigantes [the  Titanes]."
Callimachus, Fragment 195 (from Eustathius) : 
“To behold again Mekone (Poppy), seat of the Blessed (Makaroi),  where first the gods cast lots and apportioned their honours after the  war with the Gigantes [meaning here the Titanes]."
Lycophron, Alexandra 697 ff (trans. Mair) (Greek poet C3rd B.C.) :
"The dark, stream of black Styx, where Termeios [Zeus] made the  seat of the oath-swearing for the immortals, drawing the water in golden  basins for libations, when he was about to go against the Gigantes and  Titanes."  [N.B. Lycophron here conflates the Giant and Titan  wars--presumably  the Titanes were conceived in some sort of leadership  role.]
Diodorus Siculus, Library of History 5. 71. 2 (trans. Oldfather) (Greek historian C1st B.C.) :
"Before the battle against the Gigantes in Krete [the Titanes],  we are told, Zeus sacrificed a bull to Helios (the Sun) and to Ouranos  (Heaven) and to Ge (Earth); and in connection with each of the rites  there was revealed to him what was the will of the gods in the affair,  the omens indicating the victory of the gods and a defection to them of  the enemy [certain Titanes defected to the side of Zeus]. And the  outcome of the war accorded with the omens; for Mousaios (?) deserted to  him from the enemy, for which he was accorded peculiar honours, and all  who opposed them were cut down by the gods."
Strabo, Geography 10. 3. 19 (trans. Jones) (Greek geographer C1st B.C. to C1st A.D.) :
"Others say that the Korybantes, who came from Baktriana (some  say from among the Kolkhians), were given as armed ministers to Rhea by  the Titanes."
Quintus Smyrnaeus, Fall of Troy 5. 103 ff (trans. Way) (Greek epic C4th A.D.) :
"Zeus in his wrath was set upon the crest [depicted on the helm  of Akhilleus] throned on heaven's dome; the Immortals all around  fierce-battling with the Titanes fought for Zeus. Already were their  foes enwrapped with flame, for thick and fast as snowflakes poured from  heaven the thunderbolts: the might of Zeus was roused, and burning  Gigantes seemed to breathe out flames."    [N.B. The Titan and Giant Wars are here conflated.] 
Quintus Smyrnaeus, Fall of Troy 8. 460 ff : 
"On the presumptuous Titanes once in wrath he [Zeus] poured down  fire from heaven: then burned all earth beneath, and Okeanos'  world-engirdling flood boiled from its depths, yea, to its utmost  bounds: far-flowing mighty rivers were dried up: perished all broods of  life-sustaining earth, all fosterlings of the boundless sea, and all  dwellers in rivers : smoke and ashes veiled the air: earth fainted in  the fervent heat."
Ptolemy Hephaestion, New History Book 2  (summary from Photius, Myriobiblon 190) (trans. Pearse) (Greek  mythographer C1st to C2nd A.D.) :
"The tomb which passes for that of Zeus in Krete is that of  Olympos of Krete, who received Zeus son of Kronos, raised him and taught  divine things to him; but Zeus, he says, struck down his foster-parent  and master because he had pushed the Gigantes [that is, the Titanes] to  attack him in his turn; but when he had struck, before his body he was  full of remorse and, since he could appease his sorrow in no other way,  he gave his own name to the tomb of his victim."
Ptolemy Hephaestion, New History Book 6 (summary from Photius, Myriobiblon 190) : 
"Arke was the daughter of Thaumas and her sister was Iris  (Rainbow); both had win gs, but, during the struggle of the gods against  the Titanes, Arke flew out of the camp of the gods and joined the  Titanes [to act as their messenger]. After the victory Zeus removed her  wings before throwing her into Tartaros."
Anonymous (perhaps Pamprepius of  Panopolis), Fragments (trans. Page, Vol. Select Papyri III, No. 140b)  (Greek poetry C4th A.D.) :
"Zeus, the leader of the dance that slew the Gigantes . . .
Khthon (Earth) [i.e. Gaia] teemed of old and bore a son Azeios, who grew  to manhood amid the mighty battles of the Titanes. Gigas (the giant)  Azeios encountered a Nymphe with lover’s intent, and begot Lykon [the  grandfather of King Lykaon of Arkadia]."
[Cf. Eumelos' Titanomakhia Frag 3 above for the dance of Zeus.  The Gigantomakhia and Titanomakhia are here synonymous. The figure of  Azeios fixes the Titan war in the Arkadian chronology.]
Pseudo-Hyginus, Fabulae 150 (trans. Grant) (Roman mythographer C2nd A.D.) :
"Encouraged the Titanes [and Gigantes?] to drive Jove [Zeus] from the  kingdom and restore it to Saturn [Kronos]. When they tried to mount tot  heaven, Jove with the help of Minerva [Athene], Apollo, and Diana  [Artemis], cast them headlong into Tartarus. On Atlas, who had been  their leader, he put the vault of the sky; even now he is said to hold  up the sky on his shoulders."
Pseudo-Hyginus, Astronomica 2. 13  :
"Some have called Aex (Goat) the daughter of Sol [Helios the  Sun], who surpassed many in beauty of body, but in contrast to this  beauty, had a most horrible face [she was the Gorgon]. Terrified by it,  the Titanes begged Terra [Gaia the Earth] to hide her body, and Terra is  said to have hidden her in a cave in the island of Crete. Later she  became nurse of Jove [Zeus], as we have said before [and made his  aigis-shield from her skin]."
Pseudo-Hyginus, Astronomica 2. 16 :
"Aglaosthenes, who wrote the Naxica, says that Jove  [Zeus] was taken secretly from Crete, brought to Naxos, and there  nourished. After he came to man’s estate and wished to attack the  Titanes in war, he sighted an eagle as he was sacrificing, and  considering this an omen, he placed it among the stars."
Pseudo-Hyginus, Astronomica 2. 39 :
"[The constellation] Altar. On this altar the gods are thought  to have first made offerings and formed an alliance when they were about  to oppose the Titanes. The Cyclopes made it. From this observance men  established the custom that when they plan to do something, they make  sacrifices before beginning the undertaking."
Ovid, Fasti 3. 793 ff (trans.Boyle) (Roman poetry C1st B.C. to C1st A.D.) :
"Saturnus [Kronos] was thrust from his realm by Jove [Zeus]. In  anger he stirs the mighty Titanes to arms and seeks the assistance owed  by fate. There was a shocking monster born of Mother Terra (Earth), a  bull, whose back half was a serpent. Roaring Styx [as an ally of Zeus]  imprisoned it, warned by the three Parcae [Moirai the Fates], in a black  grove with a triple wall. Whoever fed the bull’s guts to consuming  flames was destined to defeat the eternal gods. Briareus [or Aigaion, a  Sea-Titan ally of Kronos] slays it with an adamantine axe and prepares  to feed the flames its innards [and so ensure the victory of the  Titanes]. Jupiter [Zeus] commands the birds to grab them; the kite  brought them to him and reached the stars on merit."
Cicero, De Natura Deorum 2. 28 (trans. Rackham) (Roman rhetorician C1st B.C.) :
"According to the myths they [the gods] even engage in wars and  battles . . . they actually fought wars of their own, for instance with  the Titanes and the Gigantes. These stories and these beliefs are  utterly foolish."
Seneca, Hercules Furens 79 ff (trans. Miller) (Roman tragedy C1st A.D.) :
"Set free the Titanes who dared to invade the majesty of Jove [Zeus]."
Nonnus, Dionysiaca 1. 378 ff (trans. Rouse) (Greek epic C5th A.D.) :
"[Zeus speaks as the monster Typhoeus approaches heaven :] `What  will my aigis [storm-cloud] do fighting with Typhon’s thunderbolt? I  fear old Kronos may laugh aloud, I am shy of the proud neck of my lordly  adversary Iapetos.'"
Nonnus, Dionysiaca 8. 67 ff : 
"I [Ares] will take my Titan-destroying deathdealing spear."
Nonnus, Dionysiaca 13. 33 ff : 
"Zeus Lord in the Highest, did not rise to heaven without hard  work, he the sovereign of the stars : firt he must beind fast those  threateners of Olympos, the Titanes and hide them deep in the pit of  Tartaros."
Nonnus, Dionysiaca 18. 223 ff : 
"[Zeus] in his first youth battered the earthborn Titanes for Olympos, when he was only a boy."
Nonnus, Dionysiaca 20. 35 ff : 
"Ares, destroyer of the Titanes, his father’s champion, who  lifts a proud neck in heaven, still holding that shield ever soaked with  gore; and . . . once upon a time valiant Pallas holding the aigis  (goatskin) defended the gates of Olympos, and scattered the stormy  assault of the Titanes, thus honouring the dexterous travail of her  father’s head."
Nonnus, Dionysiaca 24. 230 ff : 
"The singer wove his lay beside the mixing-bowl, how the older  Titanes armed themselves against Olympos. He sang the true victory of  Zeus potent in the Heights, how broadbeard Kronos sank under the  thunderbolt, and Zeus sealed him deep in the dark Tartarean pit, armed  in vain with the watery weapons of the storm."
Nonnus, Dionysiaca 27. 290 ff : 
"He [Pan] once helped to defend my [Zeus'] inviolable sceptre and fought against the Titanes."
Nonnus, Dionsyiaca 30. 283 ff : 
"[Athene addresses Dionysos :] Your father and mine [Zeus]  feared not battle, when the Titan-gods armed themselves against  Olympos."
Nonnus, Dionysiaca 36. 110 ff : 
"[Hermes addresses Poseidon and Apollon as they engage in battle  when the gods take opposite sides during Dionysos' Indian War :]  `Brother of Zeus [Poseidon, and you his son [Apollon]--you, famous  Archer, throw to the winds your bow nad your brand, and you, your  pronged trident : lest the Titanes laugh to see a battle among the gods.  Let there not be intestine war in heaven once gain, after that conflict  with Kronos which threatened Olympos : let me not see another war after  the affray with Iapetos.'"
Nonnus, Dionysiaca 19. 158 ff : 
"What an old man of Titan blood might have done, show the Titan  race in his speaking picture . . . Kronos, or Phanes more primeval  still, or the breed of Titan Helios as old as the universe itself."