His daughter married John Knox and he played a part in the defeat of Mary, Queen of Scots at the battle of Langside.
When resistance to the Catholic religion and the rule of the Regent of Scotland, Mary of Guise, began to grow, Ochiltree was one of the first of the Lords of the Congregation who marched to Perth in June 1559, and joined up with the rest at Edinburgh by 1 July.
John Knox wrote the letters, which state their "whole intent" was to remove superstition and "maintain the liberty this our country from the tyranny and thraldom of strangers."
[3] John Knox later wrote in his History of the Reformation in Scotland that Ochiltree was "a man more likely to look for peace than fight in the causeway."
As a widow Martha Stuart lived on the island of Almö, and was a frequent correspondent of the Swedish chancellor, Axel Oxenstierna, whose castle Tidö Slott was nearby.