The English longbow was a powerful medieval type of longbow (a tall bow for archery) about 6 ft (1.8 m) long used by the English and Welsh for hunting and as a weapon in medieval warfare. English use of longbows was effective against the French during the Hundred Years' War, particularly at the start of the war in the battles of Sluys (1340), Crécy (1346), and Poitiers (1356), and perhaps most famously at the Battle of Agincourt (1415). They were less successful after this, with longbowmen having their lines broken at the Battle of Verneuil (1424), and being completely routed at the Battle of Patay (1429) when they were charged before they had set up their defensive position.
The earliest longbow known from England, found at Ashcott Heath, Somerset, is dated to 2665 BC, but no longbows survive from the period when the longbow was dominant (c. 1250–1450 AD), probably because bows became weaker, broke and were replaced, rather than being handed down through generations. More than 130 bows survive from the Renaissance period, however. More than 3,500 arrows and 137 whole longbows were recovered from the Mary Rose, a ship of Henry VIII's navy that sank at Portsmouth in 1545
A longbow must be long enough to allow its user to draw the string to a point on the face or body, and the length therefore varies with the user. In continental Europe it was generally seen as any bow longer than 1.2 m (3.9 ft). The Society of Antiquaries of London says it is of 5 or 6 feet (1.5 or 1.8 metres) in length. Richard Bartelot, of the Royal Artillery Institution, said that the bow was of yew, 6 feet (1.8 m) long, with a 3-foot (910 mm) arrow. Gaston III, Count of Foix, wrote in 1388 that a longbow should be "of yew or boxwood, seventy inches [1.8 m] between the points of attachment for the cord". Historian Jim Bradbury said they were an average of about 5 feet and 8 inches. All but the last estimate were made before the excavation of the Mary Rose, where bows were found ranging in length from 1.87 to 2.11 m (6 ft 2 in to 6 ft 11 in) with an average length of 1.98 m (6 ft 6 in).
Estimates for the draw of these bows varies considerably. Before the recovery of the Mary Rose, Count M. Mildmay Stayner, Recorder of the British Long Bow Society, estimated the bows of the Medieval period drew 90–110 pounds-force (400–490 newtons), maximum, and Mr. W.F. Paterson, Chairman of the Society of Archer-Antiquaries, believed the weapon had a supreme draw weight of only 80–90 lbf (360–400 N). Other sources suggest significantly higher draw weights. The original draw forces of examples from the Mary Rose are estimated by Robert Hardy at 150–160 lbf (670–710 N) at a 30-inch (76.2 cm) draw length; the full range of draw weights was between 100–185 lbf (440–820 N). The 30-inch (76.2 cm) draw length was used because that is the length allowed by the arrows commonly found on the Mary Rose.
A modern longbow's draw is typically 60 lbf (270 N) or less, and by modern convention measured at 28 inches (71.1 cm). Historically, hunting bows usually had draw weights of 50–60 lbf (220–270 N), which is enough for all but the very largest game and which most reasonably fit adults can manage with practice. Today, there are few modern longbowmen capable of using 180–185 lbf (800–820 N) bows accurately.
A record of how boys and men trained to use the bows with high draw weights survives from the reign of Henry VII.