Also, roblrich, could you write up some Civilopedia entries (Constantine's history, history of the "Vexillationes palatinae") so we could have that for the mod?
Here's a first draft on the Palatini Cavalry. I was surprised not being able to find much info on the web at all. But I came up with this.
Palatini Cavalry
The palatini were created by Constantine I after he disbanded the Praetorian Guard in AD 312. Palatini cavalry regiments were called vexillationes. The majority of these Roman cavalry regiments were semi-armored to heavily armored types, suitable for melee combat, for harassment and pursuit, and for the shock charge. With horses draped in chain mail or plated armor, and the rider himself in an equally impressive suit of armor, these mounted units were used primarily for crushing through the lines of enemy infantry. Although these late Roman army units were used in both the east and western parts of the empire, on the Eastern frontier the cavalry played a more prominent role.
I suggest (and hope) since the Palatini Cavalry was a late Roman army unit and lasted for many hundred years that they could be made to replace the regular cavalry with the strength of 35 and 5 movement, and if possible use Constantine's banner emblem as the unit identifier (whatever it is called). It's frustrating playing unique units that only last a few turns. Myself, I set up 'most' of my games not to go past the Industrial Age. If you plan on using it as a horseman replacement, I would suggest just using the Cataphract as people will be confused why a cavalry unit is so weak. But again, my hopes are the above.
I disagree with the premise that unique units strictly adhere to the time of the leader's life. If the civilization thrived to a certain time period, especially a civilization like Byzantium and Rome, they would be leading the world in military technology.
Constantine
History
Constantine I, first Christian Roman emperor known as ‘the Great’, ruled from 306 to 337. The first Roman emperor to convert to Christianity, Constantine decreed religious tolerance throughout the empire. As emperor, Constantine enacted many administrative, financial, social, and military reforms to strengthen the empire. Constantine rescued the failing empire, continuing work started by his father, Constantius. But he also reinvented the empire' restoring peace, stability and security by promoting harmony and tolerance, abandoning Rome to establish a more easily defensible capital at Constantinople.
Early Life
Constantine was the son of Flavius Valerius Constantius, a Roman army officer, and his consort Helena. His father became Caesar, the deputy emperor in the west in 293. Constantine was sent east, where he rose through the ranks to become a military tribune under the emperors Diocletian and Galerius. In 305, Constantius was raised to the rank of Augustus, senior western emperor, and Constantine was recalled west to campaign under his father in Britannia.
Rise to Power
After his father's death in 306, his soldiers proclaimed Constantine emperor, but much rivalry for the vacated office ensued. Constantine emerged victorious in a series of civil wars against the emperors Maxentius and Licinius to become sole ruler of both west and east by 324.
Constantine as sole ruler of the empire while in a reign of peace, he set about rebuilding the strength of old Rome. Constantine continued to tolerate paganism and even to encourage the imperial cult. At the same time, however, he endeavored to unify and strengthen Christianity.
Whatever else you need just ask. Please keep us apprised of the mod's progress. I anxiously await it's completion.