Julius Caesar.

First of the Caesars.

100 to 44 (before Christ).

Related and attributed text(s).
Gallic War (attributed), available in Latin, English, and Italian (Italian site).
Civil War (attributed), available in Latin, English, and Italian (Italian site).
Spanish War (attributed but dubious), available in Latin and English (Italian site).
African War (attributed but dubious), available in Latin and English (Italian site).
Alexandrian War (attributed but dubious), available in Latin and English (Italian site).
Velleius Paterculus, Roman History, especially 2.29-58 (related), available in Latin and English (LacusCurtius).
Suetonius, Divine Julius (related), available in Latin and English (LacusCurtius).
Cassius Dio, Roman History (related), available in English (LacusCurtius).

Useful links.
Julius Caesar at Wikipedia.
Julius Caesar at the Romans Page.

Julius Caesar was the first of the twelve Caesars for whom Suetonius wrote a biography. Though we do not customarily consider him a Roman emperor, the ancients most frequently regarded him as the first on the list of Roman emperors, kings, or Caesars.

Ovid, Fasti 3.697-710:

Praeteriturus eram gladios in principe fixos,
cum sic a castis Vesta locuta focis.
ne dubita meminisse; meus fuit ille sacerdos.
sacrilegae telis me petiere manus.
ipsa virum rapui simulacraque nuda reliqui,
quae cecidit ferro, Caesaris umbra fuit.
ille quidem caelo positus Iovis atria vidit,
et tenet in magno templa dicata foro;
at quicumque nefas ausi, prohibente deorum
numine, polluerant pontificale caput,
morte iacent merita; testes estote, Philippi,
et quorum sparsis ossibus albet humus.
hoc opus, haec pietas, haec prima elementa fuerunt
Caesaris, ulcisci iusta per arma patrem.

A. S. Kline translates as follows:

I was about to neglect those daggers that pierced
Our leader, when Vesta spoke from her pure hearth:
Donít hesitate to recall them: he was my priest,
And those sacrilegious hands sought me with their blades.
I snatched him away, and left a naked semblance:
What died by the steel, was Caesarís shadow.
Raised to the heavens he found Jupiterís halls,
And his is the temple in the mighty Forum.
But all the daring criminals who in defiance
Of the gods, defiled the high priestís head,
Have fallen in merited death. Philippi is witness,
And those whose scattered bones whiten its earth.
This work, this duty, was Augustusí first task,
Avenging his father by the just use of arms.

Michael Bird comments (weblog entry dated 11-04-2007):

This is about the apotheosis of Julius Caesar who became a god and was taken away by Vesta just before his attackers set upon him, leaving only a vague naked image or a shadow to be murdured by his assassin's daggers. What else would the gods do for one who was so great and now set among them?

You can understand then the context in which docetism emerged.