The mere legal maxim from the Code of Justinian, that "that which touches all shall be approved by all,"[15] "becomes transmuted by Edward I.into a great political and constitutional principle."[16] REPRESENTATIVE THEORY FIRST FOUND IN ECCLESIASTICAL ASSEMBLIES More than a century earlier the first recorded appearances of town representatives are found in the Spanish Cortes of Aragon and Castile.[17] St.Dominic makes a representative form of government the rule in his Order of Preaching Friars, each priory sending two representatives to its provincial chapter, and each province sending two representatives to the general chapter of the Order.
In England, Simon of Montfort, the son of Simon, the great warrior of the Albigensian wars and the warm friend of Dominic, was in close association with the friars.

Hence there was nothing so very remarkable in Earl Simon issuing writs for the Full Parliament of 1265 for the return of two burgesses from each city and borough.

He had seen representative government at work among the friars in their chapters.

Why should the plan be not equally useful in the government of the country ?[18] There is no evidence that the summons to the burgesses was regarded as a revolutionary proposal--so lightly comes political change in England.
The name of Simon of Montfort, Earl of Leicester, must always be associated with the beginning of representative government in England.

Let us recall how it was the great Earl came to be in power in 1265.
THE MISRULE OF HENRY III.
Henry III.