 After the death of his father in 1556, Sir Charles Morrison (1549–1599) continued building and completed the mansion, which had 56 rooms, a long gallery, stables, a dairy, and a brewhouse.Sir Charles was succeeded by his son, Sir Charles Morrison, 1st Baronet (1587–1628); the younger Charles had a daughter, Elizabeth Morrison (1610–1660).In 1627 Sir Charles Morrison's daughter, Elizabeth (the heir to Cassiobury), married Arthur Capell, 1st Baron Capell of Hadham (1610–1649) and the estate passed into the Capel family.