Unpopular in the west of Scotland because of his support for the Duke of Lauderdale’s anti-covenanting policies, Perth nonetheless became Lord Chancellor in 1684. The same year he was made sheriff-principal of Edinburgh and governor of Bass Rock, in the latter capacity he gained a reputation for cruelty, introducing the thumbscrew as an instrument of torture. With the accession of James VII and II, Perth converted to Catholicism and became the chief agent of the new administration in Scotland. When William of Orange arrived in 1688, Perth was imprisoned in Stirling Castle, but he was later allowed to join James on the continent and was with him until he died in 1701.