Born to Sir Owen Tudor and the dowager queen Catherine of Valois, Edmund was the half-brother of Henry VI of England.

He was raised for several years by Katherine de la Pole, and Henry took an interest in Edmund's upbringing, granting him a title and lands once he came of age.

Prior to the start of the Wars of the Roses, Edmund liaised with Richard, Duke of York, and supported him when the King fell ill during 1453–1454.

Edmund was captured and imprisoned at Carmarthen Castle, where he died of the bubonic plague on 3 November 1456, three months before the birth of his son, the future Henry VII.

Following the death of Henry V of England, the Queen dowager Catherine of Valois married Owen Tudor.

[3] As earls and half-brothers of the king, Edmund and Jasper had unparalleled precedence over all other non-clerics in the court, with the exception of the dukes.

After the death of Humphrey, Duke of Gloucester, the royal line was at risk, and the Tudor brothers were considered as possible heirs.

After a petition by the House of Commons of England, both Jasper and Edmund were recognised officially as legitimate half-brothers of the king and the statutory disabilities associated with being considered Welsh were removed.

While York cancelled the majority of the grants Henry had made during his reign, those to Edmund and Jasper were exempt.

Both brothers were absent when the second session of Parliament that year began on 12 November;[9] Edmund had been sent to Wales to put down the rebellion of Gruffudd ap Nicolas.

Edmund died a year later, leaving a 13-year-old widow who was seven months pregnant with their child, Henry Tudor.

Gruffudd made war with the troops under Edmund, capturing the castles at Aberystwyth, Carmarthen and Carreg Cennen by June 1456.

The rebellion didn't last long, and by early August, Edmund's forces had retaken those castles although minor skirmishes continued for several months longer.

There were suspicions that Edmund may have been murdered, and so a trial was held several months later with several parties accused, but no one was found guilty.

Edmund's remains were removed to the choir of St David's Cathedral, Pembrokeshire, in 1539, due to the dissolution of the monasteries enacted by his grandson, King Henry VIII of England of the Royal House of Tudor.