Grosmont, along with its sister castles Skenfrith and White, was built to protect one of the main routes through the border region between England and South Wales. In the early twelfth century  King Stephen brought all three castle together under a single Lordship that controlled the 'Three Castles' as one defensive unit.

The name "Grosmont" is derived from the French "gros mont" meaning "big hill", an apt name for the large mound on which the castle is built. By the early 15th century the castle had played its last military role and by the 16th century all three castles had been abandoned and were falling into ruin.

The castle is hidden at the back of the village houses with access to the castle easily missed, so you'll have to look out for the lane that leads to the castle. This is a fabulous castle to explore.

~ History ~

1066 - A few months after the Battle of Hastings, William the Conqueror makes one of his principle supporters, William fitz Osbern, Earl of Hereford.

1070 - Fitz Osbern invades South Wales and builds castles at Chepstow and Monmouth. He identifies a site at Grosmont for the building of another castle.

1071 - Fitz Osbern is killed in Flanders.

1075 - William's son and heir is involved in a rebellion against King William and forfeits his lands.

1100's - The stone hall at Grosmont is built by the powerful Marcher baron Payn Fitz John.

1134 - Rebellion breaks out in Wales.

1137 - Payn Fitz John is killed in action fighting the Welsh.

1139 - Grosmont is taken from King Stephen in rebellion by Brian Fitz, Count of Abergavenny. Three years later he grants the castle by charter to Walter Hereford.

1160 - Walter is killed fighting in the Holy Land and so King Henry reclaims the castle for the Crown and garrisons it.

1182 - Welsh forces attack and burn castles including Abergavenny.

A year later the timber castle at Grosmont is strengthened in readiness of further attacks.

1201 - The castle is granted to the powerful baron Hugh de Burgh.

1205 - De Burgh is near mortally wounded in the Loire valley defending King John's key castle of Chinon in a year long siege. In recognition of his deeds King John hands De Burgh lands and castles to his arch rival William de Braose, Lord of Abergavenny.

1219 - Following the signing of Magna Carta in 1215 and King John's death in 1216, Hubert de Burgh recovers his lands and castles. The twelve year old King Henry III succeeds to the throne.

1224 - Hubert undertakes major building work at Grosmont.

1233 - Grosmont witnesses the rout of King Henry III's army who are camped outside the castle, by rebel English and Welsh forces during a night attack, who include in their midst Hubert. Six years later Hubert falls from grace and his lordship is lost.

1254 - The 'Three Castle's are granted to the Lord Edward, the future King Edward I.

1260's - Llywelyn the Last overrun's much of South Wales .

1267 - King Henry III grants Grosmont to his second son Prince Edmund 'Crouchback' Earl of Lancaster, who remodels the castle over a twenty year period between 1274 and 1294.

1405 - Sir John Talbot defeats Owain Glyndwr's Welsh forces who lay siege to Grosmont. Glyndwr's son is captured at nearby Usk and is sent to the Tower of London where he later dies.