Another Galaxy…another time.

30,000 Years BBY (BB=Before the Battle of Yavin):

The hyperdrive is invented. This technology allows starships to “jump” into another dimension in which travel time between stars is drastically reduced. This allows a truly Galactic Civilization to begin to form.

*Prior to this Warp Drives did allow practical interstellar travel, but only within local star clusters. Maximum speeds achievable with Warp Drive would allow a starship to cross the galaxy in 200 years.

*Warp Drive is needed to explain how, in ESB, the Millennium Falcon can get from one star system to another in a short period of time (was it weeks or months in the film?) without a functioning Hyperdrive.