When was the British Parliament convened?

The first convocation took place in 1265. At the very beginning of this year, the establishment of parliament was initiated by Simon de Montfort. He was the leader of the resistance of the English barons, organized in relation to King Henry III. After defeating the royal supporters, Montfort became for a time Lord Protector. For parliamentary sessions, he invited barons loyal to his regime, as well as bishops and abbots. Also, each county delegated 2 knights, and each major city – 2 citizens.