Complex sentence: Postnik Yakovlev (Постник Яковлев), is most famous as the architect and builder of Saint Basil's Cathedral on Red Square in Moscow (built between 1555 and 1560).
Split into simpler sentences: Postnik Yakovlev (Постник Яковлев), was the architect of St. Basil's Cathedral in Moscow. He is most famous as the architect and builder of Saint Basil's Cathedral on Red Square in Moscow (built between 1555 and 1560).