Percy Simpson (1865-1962) was educated ar Selwyn College, Cambridge, and after a career as a schoolmaster, came to Oxford in 1913 to work for the Clarendon Press and to lecture in the School of English. From 1914 to 1934 he was also the School's first Librarian. His monumental edition of Ben Jonson was published by the Clarendon Press, 1925-52. See the Dictionary of National Biography and A list of the published writings of Percy Simpson (Oxford, 1950) for further details.
From the guide to the Papers of Percy Simpson, early 20th century, (University of Oxford, English Faculty Library)