On this day, January 18, in 1425, Edmund Mortimer, 5th Earl of March died at Trim Castle, on the south bank of the River Boyne in County Meath, Ireland. At the time of his death, Edmund was only a distant cousin of King Henry VI of England, with limited fortune and slim career prospects at court. However, he was a controversial figure in England and his death caused the royal family a certain amount of relief since some of his contemporaries maintained he, and not Henry VI, was the rightful king.
Henry VI’s grandfather, Henry IV, was the founder of the House of Lancaster after deposing the last Plantagenet king, Richard II, in 1399. Richard II’s claim to the throne was undeniable – he had been the only surviving son of the monarch’s eldest son (Edward, the Black Prince) – and he had smoothly inherited the throne from his grandfather, Edward III, in 1377 at 10 years old. It was less clear, however, who his own heir was since he, despite two marriages, was childless.
While today the laws of succession are clearly defined, it was bit murkier in the 14th century and Richard II’s own choice of his many uncles and cousins would have held significant sway, even if they were not next in birth order. The most powerful of Richard’s uncles – the sons of Edward III – was John of Gaunt, Duke of Lancaster. He was enormously wealthy, politically savvy and had decades of governing and military experience – he also had a capable heir, Henry of Bolingbroke, Duke of Hereford. However, Gaunt wasn’t popular with his nephew the King and there were many at court that mistrusted his ambition – afraid that he would end up with too much centralized power during Richard’s minority or, worse, would attempt to seize the throne for himself.