This translated excerpt from Froissart's account of the execution is given, for example in: Sponsler, C. (April 2001). Burger, G.; Kruger, S. F. (eds.). Queering the Middle Ages. Medieval Cultures Series. University of Minnesota Press. p. 152. ISBN978-0-8166-3404-0.
bbc.co.uk
bbc.co.uk
BBC gives "c. 1287" ("This Sceptred Isle".); Alison Weir (2005) writes that he was "at least three years younger" than Edward II (page 115), which indicates a birth no earlier than 1287.
Hamilton, J. S. (January 2008) [2004]. "Despenser, Hugh, the younger, first Lord Despenser (d. 1326)". Oxford Dictionary of National Biography (online ed.). Oxford University Press. doi:10.1093/ref:odnb/7554. (subscription required)