On 10 March 1322 Edward II stood at the head of an army at Burton, by the river Trent. Confronting him were forces led by Thomas, earl of Lancaster, and Humphrey de Bohun, earl of Hereford, whose hostile intent was signified by the flying of their banners. According to the lively account of the Gesta Edwardi de Carnarvan, Edward wanted to raise his own royal banner, as battle was imminent. However, Hugh Despenser the younger dismounted from his warhorse and prostrated himself before his king, begging him:

As this speech put into Despenser's mouth suggests, the decision as to whether or not to unfurl the king's banners was of great import, for, in medieval law, the raising of banners signified the legal existence of a state of war – and so, for a leader to unfurl his banners at the head of an army amounted to a declaration of war. Conversely, Edward's decision not to unfurl the royal banner indicated that – as far as the Crown was concerned – the fighting against Lancaster did not legally constitute a state of war.

This scene marked the final escalation of an acute political crisis occasioned by the rapid rise to overweening prominence of the new royal favourite, Hugh Despenser the younger, alongside his like-named father, a longstanding supporter of the king. In May 1321, incensed by the predatory acquisitiveness of the younger Despenser, which was aided and abetted by the king, a number of English magnates had mounted a series of co-ordinated armed attacks on the Despensers’ lands, centring on the Welsh Marches.