Edward I, also known as Edward Longshanks and the Hammer of the Scots, was King of England from 1272 to 1307. Concurrently, he was Lord of Ireland, and from 1254 to 1306 he ruled Gascony as Duke of Aquitaine in his capacity as a vassal of the French king. Before his accession to the throne, he was commonly referred to as the Lord Edward. The eldest son of Henry III, Edward was involved from an early age in the political intrigues of his father's reign. In 1259, he briefly sided with a baronial reform movement, supporting the Provisions of Oxford. After reconciliation with his father, he remained loyal throughout the subsequent armed conflict, known as the Second Barons' War. After the Battle of Lewes, Edward was held hostage by the rebellious barons, but escaped after a few months and defeated the baronial leader Simon de Montfort at the Battle of Evesham in 1265. Within two years, the rebellion was extinguished and, with England pacified, Edward left to join the Ninth Crusade to the Holy Land in 1270. He was on his way home in 1272 when he was informed of his father's death. Making a slow return, he reached England in 1274 and was crowned at Westminster Abbey.

The monarchy of the United Kingdom, commonly referred to as the British monarchy, is the form of government used by the United Kingdom by which a hereditary monarch reigns as the head of state, with their powers regulated by the British Constitution. The term may also refer to the role of the royal family within the UK's broader political structure. The current monarch is King Charles III, who ascended the throne on 8 September 2022, upon the death of his mother, Queen Elizabeth II.