The Battle of Shrewsbury was a battle fought on 21 July 1403, waged between an army led by the Lancastrian King, Henry IV, and a rebel army led by Henry "Hotspur" Percy from Northumberland.

The battle was fought at what is now Battlefield in Shropshire, England, some three miles north of the centre of Shrewsbury. It is marked today by Battlefield Church.

The Percys had previously supported Henry IV in a war against Richard II, which ended when Henry took the throne in 1399. They subsequently supported him in Wales, early in the rebellion of Owain Glyndwr, and in Scotland, in both negotiations and conflict against the Scots. King Henry IV had been supported by a number of wealthy landowners to whom he had promised land, money and royal favour in return for their continued support and when the war ended, lands in and around Cumberland promised to the Percys were instead given to a rival. This was enough to spark them into private revolt, which may have been increased when monies promised by Henry never materialised. The Earls of Northumberland and Worcester therefore publicly renounced their allegiance to the King. They charged him with perjury based on his claiming the throne instead of just his old lands and titles; his taxing the clergy despite having promised not to without the consent of Parliament; imprisoning and murdering King Richard II, and not permitting a free Parliamentary election and refusing to pay a just ransom, requested by Owain Glyndwr, who was then holding Edmund Mortimer.

Henry Percy raised a small group of retainers initially (probably about 200) in early July 1403 and started the long march south to meet his uncle, Thomas Percy, 1st Earl of Worcester. Although some nobles, such as Lord Bardolf, joined him, he recruited most of his army in Cheshire, an area hostile to Henry IV, and which provided many experienced soldiers, notably its Cheshire archers, some of whom had served as Richard II's bodyguard. It appears that he may have hoped to be reinforced by a Welsh force under the self-proclaimed Prince of Wales, Owain Glyndwr. This didn't happen, and it appears that Glyndwr, at the time fighting in Carmarthenshire, was unaware that Hotspur had acted. Nevertheless it appears some Welsh forces from the Cheshire borders may have joined him. The rebels then marched towards Shrewsbury, the heavily defended county town of Shropshire.

King Henry IV himself only became aware of these developments on July 12, apparently while he was marching an army north to assist the Percys against the Scots and received the news at Burton-on-Trent. He may well have anticipated the Percys's change of heart but nevertheless instantly switched plans to meet the immediate threat posed by the Percys. He changed direction and marched west towards Shrewsbury with his army. Estimates of the sizes of the two armies vary widely, and the medieval chronicles are subject to the usual exaggerations. It is unlikely that Percy had more than 3,500 men and the King perhaps 4,500.

Both forces arrived near the town on July 20, 1403 and set up camp to the north and south of the Severn River, which loops around the town. Hotspur based himself initially at the house of a William Betton, his army camping close to the town. The next day the King's forces crossed the River Severn at Uffington, about a mile to the east of Shrewsbury endeavouring to cut Percy's line of retreat on Chester. This they failed to do and the armies took up position in a field that is variously named: "Haytleyfield", "Husefeld", "Berwykfeld", "Bolefeld" etc. What is certain is that the battle commenced in the manor of Harlescott about a mile south west of where Battlefield church now stands. (The owner of this manor, Richard Hussey swore to this fact under oath in the escheator's court in January 1416). The battle took place in a large field of growing peas.