Bartholomew de Badlesmere, 1st Baron Badlesmere (1275 - 14 April 1322), English nobleman, was the son and heir of Gunselm de Badlesmere (died 1301) and Joan FitzBernard, and fought in the English army both in France and Scotland during the
later years of the reign of Edward I of England.
In 1307 he became governor of Bristol Castle. Edward II appointed him steward of his household. Badlesmere made a compact with some other noblemen to gain supreme influence in the royal council. Although very hostile to Thomas, Earl of Lancaster, Badlesmere helped to make peace between the king and the earl in 1318, and was a member of the middle party which detested alike Edward's minions, like the Despensers, and his violent enemies like Lancaster.
The king's conduct, however, drew him to the side of the earl, and he had already joined Edward's enemies when, in October 1321, his wife, Margaret de Clare refused to admit Queen Isabella to her husband's castle at Leeds in Kent. The king
made an assault on the castle; eventually capturing it. When he seized and imprisoned Baroness Badlesmere and their five children, civil war broke out.
After the defeat of the Earl of Lancaster at the Battle of Boroughbridge, Badlesmere was captured, attainted, and hanged, drawn and quartered at Blean near Canterbury on 14 April 1322. His head was displayed on the Burgh Gate at Canterbury.
His only son Giles, died in 1338, and then the Badlesmere estates were divided among Giles' four sisters, the daughters of Bartholomew and Margaret.
His daughter Elizabeth de Badlesmere (1313 – 8 June 1356), was married firstly (27 June 1316) to Sir Edmund Mortimer (1302 – 17 December 1331), eldest son of Roger Mortimer, 1st Earl of March and Joan de Geneville, Baroness Geneville. Both
were the parents of Roger Mortimer, 2nd Earl of March. Elizabeth de Badlesmere married secondly to William de Bohun, 1st Earl of Northampton; their son was Humphrey de Bohun, 7th Earl of Hereford.
See also the history of Chilham Castle, which was held from time to time by his descendants until the reign of King Henry VIII.