They were negotiated and signed by the Guardians of Scotland, who were ruling in Margaret's name due to her age.
Edward I was able to broker her transfer from Norway, assuaging Eric's fears with his own personal guarantees for the infant girl's safety and also settling the matter of the outstanding dowry payments which Alexander III still owed to Eric for the marriage of his daughter, also named Margaret, to the Norwegian king.
[2] Under the condition that Margaret would marry Edward's son, Scotland was to remain "separate and divided from England according to its rightful boundaries, free in itself and without subjection."
The treaty proved ineffectual, both because Margaret died en route to Scotland in 1290, and because English negotiators had included enough reservations to render the independence clauses useless.
In 1291 Edward summoned the Scottish nobles to meet him at Norham-on-Tweed and styled himself overlord of Scotland ('Lord Paramount of Scotland') and challenged claimants to the Scottish throne to recognise himself as a feudal superior as a condition of his agreeing to arbitrate the various claims.