Yes and no. On one hand PTSD and even its precursor names were not classified yet as contemporary psychology wasn’t around yet. There is not much written on subject of the disorder except for fairly recent history with the growth of psychology and the massive conflicts of the past century+.

On the other are inferences that can be made using accounts from the past. The Greek historian Herodotus wrote of a solider going blind as a result watching a fellow soldier die rather than being wounded. In literature there are inferences made to what would now be considered PTSD ranging from religious text (the book of Job) and Shakespeare’s Henry IV to Charles Dickens Tale of Two Cities. Jonathan Shay’s Achilles in Vietnam argues that the Iliad depicts PTSD (it was required reading for a Naval Postgraduate school course I was sent to and I highly recommend it).

The research into PTSD over the past few decades have pointed to a number of factors and causes that lead the disorder ranging from ethnicity, genetics, substance abuse, brain chemistry, brain injury/trauma, social interaction, mentality, and the trauma/violence itself among a myriad of others. Various names have been used in the past: nostalgia, soldier's heart, shell shock, battle fatigue, combat stress reaction (CSR), etc. It’s is not just combat that can result in PTSD but other tragedies such as abuse, sexual assault, traffic collision etc. (also see: http://www.ptsd.va.gov/public/PTSD-overview/basics/history-of-ptsd-vets.asp)