On 10 March 1415, Henry V commanded the mayor, aldermen and ‘certain of the more substantial commoners’ of London to come to the Tower where he explained to them his plans for the invasion of France. On 14 March a delegation comprising the archbishop of Canterbury, the bishop of Winchester and the dukes of Bedford, Gloucester and York went to meet the city fathers so that ‘they might more willingly contribute money to the campaign’. This element of careful advance planning had been missing in the summer of 1412. Through the oath of their ambassadors on 18 May 1412 to the terms of the treaty of London, the dukes of Berry, Orléans and Bourbon and the other Orléanist lords promised Henry IV that, if he would reverse his current alliance with the duke of Burgundy and send an army to France to support them against Burgundy, they would undertake to restore every part of the duchy of Aquitaine presently outside English jurisdiction. The promise appeared to be so good that the immediate preparation of a sizeable expeditionary force was justified. That the promise was actually too good to be true became apparent very quickly – but not until shortly after the English force had landed in France. In order that the treaty commitments might be met in a timely fashion, there followed a period of intense administrative, political and military activity against a background of serious tension within the house of Lancaster itself.