The parliament of 1327 was a watershed event. For the first time since the Norman Conquest, an English king was disposed peaceably, and not usurped by military means. Although Edward II had been previously threatened with deposition in 1310 and 1321, all those who attended the parliament of 1327 were aware of the constitutional crisis. The king was imprisoned by his Queen Isabella and her paramour Roger Mortimer after their invasion of England. The Parliament was a legal pretense to confer legitimacy upon their actions. The Lords Temporal and the Lords Spiritual were summoned in the King's name, while the Knights of the Shire, Burgesses from the towns, and representatives from the Cinque Ports were elected to attend. (Note 13: Richardson and Sayles 1930 p 44–45) According to Michael Prestwich: "What was necessary was to ensure that every conceivable means of removing the King was adopted, and the procedures combined all possible precedents".(citation needed) Hence, establishing the legitimacy of Edward III was paramount. But it was the Knights of the Shire and Burgesses (hereafter referred to as "the commons") who drove the proceedings, both before and after Edward III's coronation. Beginning in 1327, the commons became a permanent part of parliament.