The current Deputy Grand Master and Governor is Lord Elgin. Previously his father was Governor, but he stood asside for H.R.H. Edward, Prince of Wales and Duke of Rothesay (later King Edward VIII.)
Most Recent Grand Master
Briefly, the seat of Hereditary Grand Master was filled by King Edward VIII, as he was already Deputy Grand Master and Governor of the Royal Order of Scotland at the time of his Coronation. Furthermore, his brother , King George VI was meant to join the Order, but did not do so prior to his ascention to the Throne and thereafter did not have an opportunity to attend a meeting.