The accord, overall, entailed a plan developed by Henry VIII of England to unite both kingdoms (i.e. Union of the Crowns).
In this part of the treaty, it was agreed that Mary would be accompanied by an English nobleman/gentleman (and his wife) until she was ten years old.
[1] Even though the Earl of Arran signed the accord on 1 July and ratified it on 25 August 1543, the Treaty of Greenwich was ultimately rejected by the Parliament of Scotland on 11 December 1543, leading to eight years of Anglo-Scottish conflict known as the Rough Wooing.
[2] The treaty was the culmination of diplomatic efforts by Adam Otterburn, George Douglas of Pittendreich and Earl of Glencairn in London, and Ralph Sadler in Edinburgh.
[3] The commissioners for Mary (with the consent of Regent Arran) were Glencairn, Pittendreich, William Hamilton, James Learmonth of Dairsie and Henry Balnaves.