What started as a land dispute between Owain Glyndwr, a wealthy land owner in Wales and his rival Lord Grey of Rutin quickly escalated into a revolt when the English King Henry IV sided with Rutin and awarded him the land.

Glyndwr's revolt spread and he proclaimed himself the Prince of Wales. He was joined by the Tudor brothers from Anglesey and began guerrilla warfare against the English in the North of Wales and the Marcher Lords in the centre.

King Henry IV moved into North Wales to try and stop the rebellion of Owain Glyndwr, but he was not able to deal with the Welsh rebels, who were more skilled at fighting in the terrain.

The king assembled an army at Shrewsbury Castle in preparation to fight Owain Glyndwr.

Edmund Mortimer's army met Owain Glyndwr at Pilleth near Whitton in central Wales. Mortimer's army was badly defeated and Mortimer was captured. Glyndwr offered to release Mortimer for a large ransom, but Henry IV refused to pay.

The castle at Abergavenny was attacked and burnt by Owain Glyndwr.

The Norman Llansteffan Castle was attacked by Owain Glyndwr. Glyndwr may have held the castle for a short time until it was retaken by Sir John Penress (Pennes).

Owain Glyndwr's forces attacked Kidwelly Castle managing to set fire to the unfinished gatehouse but did not capture the castle.

Owain Glyndwr attacked and badly damaged Weobley Castle.

The Welsh captured Harlech Castle and the fortress became the base for Owain Glyndwr's revolt.

Owain Glyndwr attacked and captured the town of Cardiff and its castle.

Owain Glyndwr captured the town of Aberystwyth and its castle after a lengthy blockade.

Bangor Cathedral was captured by Owain Glyndwr after a siege and destroyed by fire.

Owain Glyndwr called a Parliament where he declared himself to be the true 'Prince of Wales'. Embassies from France and Scotland attended the meeting and gave promises to support Glyndwr's plans to overthrow Henry IV.

Owain Glyndwr, Edmund Mortimer and the Earl of Northumberland combine forces and share the same goal of removing Henry IV. They agreed to divide England and Wales in three, Owain taking Wales and the west of England, the Earl to take the north of England and the north Midlands. Mortimer could have the rest.

English forces fought and defeated Welsh forces in two battles at Grosmont and Usk. Sir John Talbot defeated Glyndwr at Grosmont and Prince Henry forced the Welsh to flee at Usk. Glyndwr's eldest son was captured at Usk and sent to the Tower of London where he died.

The English besiege the Welsh in Harlech Castle.