Publius Crassus
Caesar identifies Troucillus as an "adulescens", a young man, generally in Caesarian usage between the ages of 20 and 30 and not having yet entered the political career track or held a formal command. The term is used elsewhere in the "Bellum Gallicum" for Publius Crassus and Decimus Brutus, who were born in the mid-80s.