Complex sentence: Their children included Andrew Stewart, 2nd Lord Ochiltree father of Margaret who married John Knox, and the soldier and politician James, who became Earl of Arran and dominated Scottish politics after the Ruthven regime until his fall in 1585.
Split into simpler sentences: Their children included Andrew Stewart, 2nd Lord Ochiltree, who went on to father both Margaret who married John Knox, and to father the soldier and politician James. This grandson of Andrew and Lady Hamilton became Earl of Arran and dominated Scottish politics after the Ruthven regime until his fall in 1585.