Edward I was informed of the looming threat of civil war by the Bishop of St Andrews, who asked him to help prevent war and bring stability to the country.
The Guardians invited Edward to select the next King of Scotland. The English king arrived at the Scottish border in April 1291 with a large army, which worried the Guardians.
Edward I forced the Guardians to meet him at Norham Castle, on the English side of the border.
Edward told the Guardians that before he made any decision on who should become the new king of Scotland, the nobles would have to accept him as their overlord (a King or lord, who holds power over other lords).
This was not usual and had dangerous implications for Scotland:
The Guardians replied that only a King could deal with such a demand, so this could only happen after Edward had chosen a King.