Complex sentence: They were kings of the Purang-Guge kingdom whose ancestry is traced to the ancient Tibetan monarchy, and extended their kingdom from Ladakh to Mustang by building a large network of trade routes, and built temples along the route.
Split into simpler sentences: They were kings of the Purang-Guge kingdom whose ancestry is traced to the ancient Tibetan monarchy. They extended their kingdom from Ladakh to Mustang by building a large network of trade routes, and built temples along the route.