Complex sentence: This fort may have continued as a defensive work and settlement until Margraf Leopold III decided to move his main residence here in 1113 A.D. In 1133 A.D., he founded the Augustinian Abbey, which now lies over the site of the fort and dominates the City.
Split into simpler sentences: This fort may have continued as a defensive work and settlement until Margraf Leopold III decided to move his main residence here in 1113AD. In 1133AD, he founded the Augustinian Abbey, which now lies over the site of the fort and dominates the City.