Minor nobleman as Lord of Selbourne in Hampshire in 13th Century and Bailiff of Alton (1232); also Knight of the Garter. The Charles Roll of 1285 records his arms as 'Gules (red) three fleur de lis argent (silver). He had at least two wives of whom Armeria and Constantia are recorded. It is probable that a relative of his, Bertrand de Gurdon, was the French crossbowman who shot the  bolt into the shoulder of King Richard which resulted in his death. Adam de Gurdon sided with the Simon de Montfort faction against Henry III (1216 - 1272) and was probably at the Battle of Lewes in 1264 where Henry's forces were defeated. As his lands were at the disposal of King Henry, he was stripped of them all and forced to turn to brigandage for survival. Following de Montfort's defeat at the Battle of Evesham in 1265, most of the rebels took a stand in the fastness of Kenilworth Castle. Adam de Gurdon plied his new found trade as a highwayman in the notorious Pass of Alton (near Basingstoke) in Hampshire where travellers were robbed on their way between London and the south coast.

In 1266, King Henry, knowing that Sir Adam's days were numbered, arranged for young Prince Edward (the future Edward I) to  fight a hand to hand combat with Adam which, unsurprisingly, Edward won. Adam was then pardoned and this example of the king's generous nature was communicated to the rebels with a view to encouraging them to surrender. This they did although probably on very onerous terms. Adam was taken firstly to Farnham Castle and then to Guildford Castle where he was held for a while. It seems that he then found favour as he is said to have prospered.. Despite having regained his lands, he continued to obtain more land through violence and, by a warrant of 'destringas'  in 1282 was forced to restore lands to the Bishop of Winchester. He did, however, give some of his own lands to the villagers of Selbourne in 1270 and to the Priory in 1271. King Edward always held Sir Adam in high regard and made him Warden of Wo(o)lmer Forest. Sir Adam lived to a great age and is buried in St. Mary's Chapel in Selbourne (founded 1305).