
January 1329: Isabella rides against the earl of Lancaster, dressed in armour and mounted on a war horse
On a cold January morning in 1329 Roger Mortimer, Isabella and Edward III are making preparations to face the forces of Henry, the Earl of Lancaster's forces head on. In late 1328 Lancaster, supported by Edmund, the Earl of Kent and his brother Thomas, the Earl of Norfolk had demanded the removal of Roger Mortimer from court. The hostilities escalated and Mortimer declared war on Lancaster, resulting in what is known as Henry of Lancaster's Revolt of 1328-29.
The forces were not far from each other near Bedford.
Lancaster held a council with his fellow lords. He declared that they had no choice: a fight against the king was now necessary. This was not what had initially been agreed, the fight was supposed to be against Roger Mortimer with his destruction being the only goal. This change in circumstances made Kent and Norfolk recoil, and they denounced Lancaster then and there, refusing to take up arms against their king. They left, abandoning the earl to the mercy of Mortimer.
Roger Mortimer heard about the desertion as he was in Northampton. He ordered his troops for an immediate night attack. Even Isabella took part, dressed in armour and mounted on a war horse. Through the night he led them, for twenty-four miles, arriving within sight of Lancaster's camp near Bedford at daybreak. Henry made no attempt to defend himself. He came out of his pavilion and walked slowly forward through the cold January morning, and knelt down, alone, in the mud. He waited there until Roger, Isabella and Edward rode up. They watched him from their horses as he begged for forgiveness.
Source:
Ian Mortimer - 'The Greatest Traitor'