The victors of Wakefield were joined by Margaret's army and marched south, plundering settlements along the way. They liberated Henry after defeating the Yorkist army of Richard Neville, Earl of Warwick, in the Second Battle of St Albans and continued pillaging on their way to London. The city of London refused to open its gates to Henry and Margaret for fear of being looted. The Lancastrian army was short of supplies and had no adequate means to replenish them. When Margaret learned that Richard of York's eldest son, Edward, Earl of March, and his army had won the Battle of Mortimer's Cross in Herefordshire and were marching towards London, she withdrew the Lancastrians to York. Warwick and the remnants of his army marched from St Albans to join Edward's men and the Yorkists were welcomed into London. Having lost custody of Henry, the Yorkists needed a justification to continue the rebellion against the king and his Lancastrian followers. On 4 March Warwick proclaimed the young Yorkist leader as King Edward IV. The proclamation gained greater acceptance than Richard of York's earlier claim, as several nobles opposed to letting Edward's father ascend the throne viewed the Lancastrian actions as a betrayal of the legally established Accord.