 In 1520 he was already a Carthusian, and was employed by Edward Lee (afterwards archbishop of York) in connection with his critical attack upon Erasmus.Erasmus (from whose letters we learn this fact) gives a spiteful sketch of his character—‘unlearned, to judge from his writings, and boastful to madness.’ In 1523, according to Tanner, on the authority of a manuscript belonging to Bishop Moore, he was prior of the Charterhouse of Hinton in Somerset; but his name has escaped the researches of Dugdale and his later editors, both in connection with Hinton and London.On the death of William Tynbigh, prior of the London Charterhouse, in 1529, Batmanson was elected to succeed him.