The late historian Paul Murray Kendall, on the other hand, maintained that Margaret's allies Edmund Beaufort (Somerset) and William de la Pole, then Earl of Suffolk, had no difficulty in persuading her that York, until then one of Henry VI's most trusted advisers, was responsible for her unpopularity and already too powerful to be trusted. Margaret not only convinced Henry to recall York from his post as governor in France and banish him instead to Ireland, she repeatedly attempted to have him assassinated during his travels to and from Ireland, once in 1449 and again in 1450. Edmund Beaufort (Somerset) and Suffolk's joint responsibility for the secret surrender of Maine in 1448, and then the subsequent disastrous loss of the rest of Normandy in 1449 embroiled Margaret and Henry's court in riots, uprisings by the magnates, and calls for the impeachment and execution of Margaret's two strongest allies. It also might have made an ultimate battle to the death between Margaret and the House of York inevitable by making manifest Richard's dangerous popularity with the Commons. Richard of York, safely returned from Ireland in 1450, confronted Henry and was readmitted as a trusted advisor. Soon thereafter, Henry agreed to convene Parliament to address the calls for reform. When Parliament met, the demands could not have been less acceptable to Margaret: not only were both Edmund Beaufort (Somerset) and Suffolk impeached for criminal mismanagement of French affairs and subverting justice, but it was charged as a crime against Suffolk (now a duke) that he had antagonised the king against the Duke of York. Further, the demands for reform put forward included that the Duke of York be acknowledged as the first councillor to the king, and the Speaker of Commons, perhaps with more fervour than wisdom, even proposed Richard, Duke of York, be recognised as heir to the throne. Within a few months, however, Margaret had regained control of Henry, Parliament was dissolved, the incautious Speaker thrown in prison, and Richard of York retired to Wales for the time being.