The Great Hyperspace War wasn't really all that great. The Sith, in isolation and previously unknown to the Republic, were fighting each other for fun, when they were accidentally discovered by a couple of dumbass travelers. Now alerted to the existence of an entire galaxy with worlds to conquer, the Sith decided to invade the Republic. Although powerful and full of strong dark magic, lets face facts: this was a foolish move. The Sith attacks, while catching the Republic by surprise at first, were not nearly strong enough, and the Republic forces routed them. Sith factions fled back to their home areas, and continued to fight each other for no real reason. While futzing around, they forgot to lock the door to their home system, and were basically wiped out, except for one mysterious dude. He escaped and cultivated more Sith crap to strike back at the Republic about 1300 years later. Yawn. Anyway, some senator thought the victory was good enough to reboot the calendar to the year 0, but he was immediately analraped, killed, and analraped again by his fellow senators. It became an annual anal tradition in the Galactic Senate.