Owain Glyndwr is the preeminent national hero of Wales. From 1400 to 1415 he led a war of independence against the English under King Henry IV. The Welsh consider Glyndwr the last true—that is, native-born—prince of Wales (tywysog Cymru—pronounced TOO-a-sog CUM-ry—in Welsh). Though the English had usurped the title as early as 1282, Glyndwr’s followers proclaimed him prince of Wales on Sept. 16, 1400.

Glyndwr was the son of a wealthy landowner who served the English as a Marcher Lord in the border region between England and northeast Wales. In his youth Glyndwr studied law at the Inns of Court in London, and he later served in the English army of King Richard II, even taking part in the 1385 invasion of Scotland. Richard was favorably disposed to the Welsh. But in 1399 the king’s first cousin Henry Bolingbroke deposed Richard and assumed the throne as Henry IV. Welsh allegiance split, with Glyndwr coming down on the side supporting Richard. In Wales the opposition to Henry quickly spiraled into a general revolt against the English, with Glyndwr as its leader.

The rebels were initially very successful, particularly in north Wales. Their primary weakness was a lack of artillery, necessary for besieging castles, and as they extended their control to south Wales, they encountered stiffer opposition, including economic sanctions. In the spring of 1405 the Welsh suffered an especially costly defeat at Pwll Melyn (pronounced roughly poosch MEL-in), in southeast Wales. It marked the turning point of the rebellion.

The fight began just north of Newport on the Severn Estuary as Welsh rebels under Glyndwr’s son Gruffudd and brother Tudur besieged the English at Usk Castle. They were beaten back by its garrison, which then sortied out in pursuit. Leading the English force were Baron Richard Grey of Codnor, Sir John Oldcastle of Herefordshire, Sir John Greyndour and Dafydd Gam. Though a native Welshman, Gam had aligned with Henry and was hostile to Glyndwr and the revolt. His knowledge of the area and noble standing made it difficult for the rebels to rally the local population to their cause. The fact Glyndwr had sacked and burned Usk a few years earlier certainly did not help.

The English caught the Welsh near Pwll Melyn (Yellow Pool), a body of water about a quarter-mile northeast of the castle. Outnumbered and outmaneuvered, the rebels were crushed, suffering upward of 1,500 casualties, 300 of whom had been captured, marched back to the castle and beheaded. What especially hurt the rebels was the loss of many key leaders. Glyndwr’s brother Tudur and John ap Hywel, influential abbot of the Llantarnam Cistercian monastery, both died on the field. Glyndwrs son Gruffudd was captured and taken to the Tower of London, where he died in 1412.

Though the Welsh won a few more battles, Henry IV had all but crushed the revolt by 1409. Captured at Harlech that year, Glyndwr’s wife and two of his daughters would also die in captivity at the Tower of London. When Henry died in 1413, his son Prince Henry of Monmouth assumed the throne as Henry V. Though the young king took a more conciliatory tone, offering pardons to the Welsh rebel leaders, Glyndwr remained an outlaw. Never betrayed to the English, he disappeared from the pages of history around 1412. Rumor had it he died sometime in 1415. The mystery surrounding his final years imbued Glyndwr with a semi-mythical status on a par with the 7th century Welsh warrior-king Cadwaladr—a sleeping hero who would someday return to liberate his people. The English, meanwhile, continued to confer the title prince of Wales on the heir apparent to their throne, a practice followed to this day.

Present-day Usk Castle [uskcastle.com] is a well-preserved ruin, privately owned but open to the public. (Among its earliest builders was Anglo-Norman knight William Marshal, featured in the July 2015 Valor section.) Near the castle entrance a wooden sign points along a hiking path to the battlefield. In 2005, to commemorate the 600th anniversary of the battle, the Usk Civic Society marked the site with a blue circular plaque.