Complex sentence: In 1631 the German military services, returning from the siege of Mantua, pillaged of the country and in 1650 the castle, already partially ruined from the supported onslaughts, came nearly entire dismantled and the little remainders used built some palaces in the nearby.
Split into simpler sentences: In 1631 the German troops, returning from the siege of Mantua, pillaged of the area. In 1650 the castle, already partially ruined, was dismantled; what remained was used to build some palaces in the nearby.