Star Wars novels. Thrawn trilogy

It's five years after Return of the Jedi: the Rebel Alliance has destroyed the Death Star, defeated Darth Vader and the Emperor, and driven out the remnants of the old Imperial Starlfleet to a distant corner of the galaxy. Princess Leia and Han Solo are married and expecting Jedi Twins. And Luke Skywalker has become the first in a long-awaited line of Jedi Knights. But thousand of light-years away.

Luke and Leia face personal danger as they defend themselves and the newborn Jedi twins against the twisted ambitions of the Dark Jedi C'baoth.