Question

When was the first English Parliament called?

Answer 1

The first English Parliament was summoned by Simon de Monfort, who was in rebellion against King Henry 111d, in 1265.

In 1215, a General Council was held with King John and this became known afterwards as a parlementum. This meeting gave us The Magna Carta.

Prior to that, other assemblies of the same general sort were called the Curia Regis, and the earlier Anglo Saxon Witenegemot.

The earliest recorded Witengemot seems to be dated 755AD.

Witengemots evolved from meetings the various Germanic tribes held which were named folkmoots. These probably predate written history in Northern Europe.

So, as the other respondent said, it's a toss-up.