First Battle of St Albans
Part of Wars of the Roses
Date May 22, 1455
Location St Albans in Hertfordshire, England
Result Decisive Yorkist victory
Yorkshire rose.png House of York Lancashire rose.png House of Lancaster
Richard, Duke of York,
Richard, Earl of Warwick
Edmund, Duke of Somerset
3,000 2,000
Unknown 300
Wars of the Roses
1st St AlbansBlore HeathLudford BridgeNorthamptonWakefieldMortimer's Cross2nd St AlbansFerrybridgeTowtonHedgeley MoorHexhamEdgecote MoorLose-coat FieldBarnetTewkesburyBosworth FieldStoke Field

The First Battle of St Albans was the first battle of the Wars of the Roses and was fought on May 22, 1455 in the town of St Albans, 22 miles (35.5 km) north of London. Richard, Duke of York and his ally, Richard Neville, Earl of Warwick defeated the Lancastrians under Edmund Beaufort, 2nd Duke of Somerset, who was killed. York also captured Henry VI and had himself appointed Constable of England.

In an attempt to avoid being outflanked by the 3,000 strong Yorkist army, the Lancastrian army of 2,000 troops pulled back into the town and built barricades in Holywell Hill and St Peter's Street to defend against an attack from the fields to the east. The bulk of Henry's forces were surprised by the speed of Richard's attack; most of the army was expecting a peaceful resolution similar to the one at Blackheath in 1452, and the leaders of both sides had been negotiating minutes before the attack. However, two frontal assaults down the narrow streets against the barricades made no headway and resulted in heavy casualties for the Yorkists.

Warwick took his reserve troops through an unguarded part of the town's defences, following a path through back lanes and gardens. Suddenly the Earl appeared in the Market Square where the main body of Henry's troops were talking and resting. There is evidence they were not yet expecting to be involved in the fighting, as many were not even wearing their helmets. Warwick charged instantly with his small force, routing the Lancastrians and killing the Duke of Somerset.

The Earl then ordered his archers to shoot at the men around the King, killing several and injuring the King and the Duke of Buckingham. The Lancastrians manning the barricades realised the Yorkists had bypassed them, and fearing an attack from behind abandoned their positions and fled the town.

The First Battle of St Albans was relatively minor in military terms, but politically was a complete victory for York: he had captured the King and returned himself to complete power; his rival Somerset was dead; and Warwick's arch-enemies Henry Percy, 2nd Earl of Northumberland and Lord de Clifford both fell during the rout.