The thread title says it all, and both views have a number of learned adherents, but I would like to hear, what you all think.
It was not long after Carinus was killed by his own troops and Diocletian went to Italy, that he made the first step to the Tetrarchy, by appointing to the rank of Caesar Aurelius Maximianus, whom had served with Diocletian in Carus' army, later he was elevated to Augustus and taking the gentilicium of Valerius- some say he did this because he was formerly adopted- but it is quite likely a display of subservience to the father figure of Diocletian. But the debate of adoption aside, were theses steps part of an initial plan? Or was it simply the need for a colleague to meet the military threats and share responsibilities of government, there was not any formal division of territory at this stage, and later in 286 the Augusti begin using the epiphets Iovius and Herculius. So please share your thoughts, hopefully will be an interesting discussion