Roman empire

How did the Romans manage to effectively combine their whole empire into one unit?
The Roman empire combined their whole empire effectivly by sharing the same values, having one military, and building roads. without these similarites throught the empire they would not be able to work as one unit. they shared the same values, they valued simplisity(untill they captuerted the greek's any ways) then they valued richies and the gap between the rich and the poor became much bigger. Even though their values changed they still all valued the same things at the same time creating a bond in the fact that they belived and valued the same things and this bond that they foarmed helped them to work as one unit. They had one military wich literaly is a fighting unit, but it took people from all over the empire and made them work and act as one. but not only the people in the military were affected and turned into one unit every one worked for the same goal wich was to protect the borders and to concer new land and expand their empier. the fact that the whole empire was working twards the same goal made the empire act and seem like one unit. then there was also the fact that the Romans had roads that connectected every city. The roades were built for the military so that they would be able to travel very easaly. but the soldiers were not the only ones to use these roads, the roads were used by travelers and mercants going to other cities to sell their goods. not only did they make travel easyer and faster but they made the spread of informations alot faster to. Romans shared the same valus, had one military, and had roads all of these things made the romans seem and act like one giant unit.