Myrywether’s parentage has not been established, but it is probable that he was descended from a family with long traditions of service to the house of Lancaster: a namesake and putative kinsman had been Henry IV’s feodary of the duchy of Lancaster not long after the King’s usurpation, and had been killed fighting for him at Shrewsbury in 1403.
There is little evidence of Myrywether’s personal contacts: in 1450 he stood surety at the Exchequer for the Suffolk esquire William Hopton, and a few years later he served as one of the feoffees of John Scoryer, a fellow member of the Household.
The exact circumstances of the Middlesex elections to the Coventry Parliament of 1459 are obscure, but in the light of Myrywether’s modest social station there can be little doubt that it was his Household office that secured his return to the highly partisan assembly, in place of one of his more prominent neighbours who normally claimed a monopoly on the county seats. His colleague was a less remarkable choice, the experienced parliamentarian and former Speaker Thomas Charlton*, the leading lay landowner in Middlesex. It is uncertain what part, if any, either of the Middlesex MPs played in the Commons’ deliberations, but the degree to which both were regarded as politically reliable is emphasized by their inclusion that December in a commission to array the men of the county to fend off an expected invasion by the Yorkist lords in Calais.
When the invasion eventually came in the summer of 1460, the court’s forces were roundly defeated at Northampton and the new administration, formally established in the name of Henry VI who remained on the throne, set about the replacement of many of the personnel of the Household. Among those to escape this cull was once again Myrywether. It is not clear to what circumstance he owed his reprieve, but it may be significant that his parliamentary companion of 1459, Charlton, was appointed controller of the King’s household. Yet, whereas Charlton was also re-elected to the Parliament that assembled at Westminster in October, Myrywether had to make way for Charlton’s more important kinsman Thomas Frowyk II*. Nevertheless, he continued in the royal household even after the deposition of Henry VI, the King whom he had served for all of his adult life, and the accession of Edward IV.
In the first instance, the new King had little choice but to rely on his predecessor’s servants if he wished to retain some men of experience in his establishment, but as the early months of the reign went by he gradually began to pension some of them off.
