From a gentry family of middling rank, Mulsho and his elder brother Thomas made their way in the world by following the example of their uncle, Henry Mulsho, and becoming followers of the house of York. Thomas opted for service in France while waiting for his inheritance, and he continued his military career there after his father’s death in 1446. His decision to do so was doubtless prompted by the survival of his mother, who retained a dower interest in her late husband’s estate in Northamptonshire, as well as the generosity the dead man had shown Edmund and another younger son, William, in his will. Edmund succeeded to property at Geddington and William to the manor of Newton and land at Stanion, meaning that their elder brother’s inheritance was restricted to the manors of Stoke Doyle and Pilton and various other holdings.
Edmund also pursued a military career, and in June 1441 he crossed the Channel with the newly appointed lieutenant-general of France, Richard, duke of York.
Before crossing the Channel, Mulsho received a grant of lands in France forfeited by Denis de Heugeville.
Serving York also brought Sir Edmund rewards in the shape of offices. In 1446 the duke appointed him constable of the castle at Fotheringhay, for which he received an annual fee of five marks, and steward of that and other lordships in Northamptonshire, for which he was paid £10 p.a.
As it happened, Mulsho was absent from the realm on the first of those two dates, having accompanied the duke of York to Ireland.
Soon after returning to England in September 1450, York submitted a couple of bills to Henry VI, to assure him of his loyalty and to complain about the machinations of his political opponents. According to the second of these bills, there had been a plot to execute his chamberlain Sir William Oldhall* and to imprison himself, Mulsho and another leading retainer, (Sir) Walter Devereux I*, in the Welsh castle of Conway, either while they were on their way to Ireland or on their return.
It is possible that Poynings, in trouble for acting as a lieutenant to the rebel leader Jack Cade, was linked to the duke of York, with whom Cade himself had claimed a connexion. Sir Edmund and his brothers Thomas and William were very much associated with York’s political and military manoeuvres of 1451-2. It is uncertain if any of them accompanied the duke to his confrontation with the King at Dartford in March 1452, although they were all accused of treason in subsequent indictments. In one Mulsho and others were claimed to have held York’s stronghold of Ludlow in arms from 10 Feb. to 3 Mar., but in another he and his brothers and Thomas Mulsho’s son, John, were said to have been fermenting insurrection at Fotheringhay and elsewhere in Northamptonshire on 22 Feb.
The fortunes of York and his followers improved dramatically in March 1454, when the duke was appointed Protector of England for the first time. Early in the protectorate, he sent Mulsho and Louis Gallet, one of the King’s French secretaries, to Flanders, to negotiate the return of goods seized from the staple at Calais by the duke of Burgundy in retaliation for the piratical activities of Sir William Bonville*, Lord Bonville. The mission, for which Mulsho was paid a daily wage of 20s., proved unsuccessful because York failed to keep Bonville in check, and because it was hindered by the actions of Lords Rivers and Welles, who had seized wool and victuals belonging to the staple in lieu of unpaid wages.
It is likely that Sir Edmund died at Calais, where he drew up his last will, a lengthy and wide-ranging document.
