Edward had summoned both the Archbishops of Canterbury and York to meet their clergy in convocation to raise taxes. However, shortly after the sack of Berwick, matters had been complicated by Boniface VIII issuing his bull, 'Clericis Laicos,' which Winchelsea had used to insist that the king could only tax the Church with the Church's permission. Edward, hiding his terrible anger, had bitterly agreed. Matters were further worsened, Corbett thought, as he looked along the row of dignitaries in front of him, by plotters like Bigod and Bohun, who not only resented royal taxation but also Edward's demands to accompany him abroad to fight the French. Soon these diverse plotting groups would unite and form the same opposition Edward's father and grandfather had faced when trying to raise money for disastrous wars abroad.

Corbett stared through the haze of incense at the tall emaciated figure of the chief celebrant, Walter de Montfort: Archbishop Winchelsea had decided that the Church's case – requiring its full approval before it was taxed should be put to the king by no less a person than the Dean of St Paul's, Walter de Montfort. The archbishop's choice was a quiet, deadly insult to Edward, for the dean was a member, albeit tenuously, of the great de Montfort family who forty years ago had opposed Edward and his father, King Henry. Simon de Montfort, Earl of Leicester, one of the great barons of the time, had risen in revolt, seized the government and virtually dictated his own terms to the defeated monarch, Henry III.

Edward, then Prince of Wales, had quietly accepted such demands until he had gathered sufficient forces for a counter-attack. The ensuing civil war was a bloody, vicious affair, ending only when de Montfort was killed, hacked to pieces at the Battle of Evesham. After that the de Montforts, or most of those who had survived the collapse of Earl Simon, had gone abroad, but continued a secret war against Edward, sending assassins into the country to kill him and attacking his envoys abroad.