Complex sentence: Lynch, p.136 David's Tower was begun around 1367, and was incomplete when David died at the castle in 1371, being completed by his successor, Robert II, in the 1370s.
Split into simpler sentences: Lynch, p.136 David's Tower was begun around 1367, and was incomplete when David died at the castle in 1371. It was completed by his successor, Robert II, in the 1370s.