Complex sentence: In 1956 he was a colonel and the commander of an armoured division stationed in Budapest when he was sent to suppress the Hungarian Uprising, but on making contact with the insurgents he decided to join them, helping to defend the Kilian Barracks.
Split into simpler sentences: In 1956 he was a colonel and the commander of an armoured division stationed in Budapest. He was sent to suppress the rebellion, but on making contact with the insurgents during the Hungarian Uprising he decided to join them, helping to defend the Kilian Barracks.