Complex sentence: In 172, Lucilla and Quintianus accompanied Marcus Aurelius to Vindobona (now Vienna) in support of the Danube military campaign and were with him in March 17,180, when Aurelius died and Commodus became the new emperor.
Split into simpler sentences: In 172, Lucilla and Quintianus accompanied Marcus Aurelius to Vienna in support of the Danube military campaign. They were with him until March 17,180, when her father died and Commodus became the new emperor.