John Middleton, 1st Earl of Middleton was a professional soldier and mercenary from Kincardineshire in Scotland. Beginning his career in the Thirty Years War, during the Wars of the Three Kingdoms he fought for the Covenanters and Parliamentarians until 1648, when he switched sides to the Royalists.

The Lord High Commissioner to the Parliament of Scotland was the monarch of Scotland's personal representative to the Parliament of Scotland. From the accession of James VI of Scotland to the throne of England in 1603, a Lord High Commissioner was appointed from among the senior nobility to represent the Scottish monarch in parliament when he or she was absent, as was usually the case up to 1707. The Act of Union 1707, which merged the Parliament of Scotland and the Parliament of England to create the Parliament of Great Britain, rendered the post redundant.