Salamanca was an expensive business.[23] Confirmation of this conjecture is afforded by the fact that he speedily returned to his allegiance, was 'incorporated' as a bachelor at Salamanca in 1588, graduated there as a licentiate of theology in May 1560, and in the following month became a master of theology.[24] It soon became clear that he did not regard a University degree as a mere distinction. The retirement of Gregorio Gallo caused a vacancy in the chair of Biblical Exegesis at Salamanca. Luis de Leon, though but a master of a few months' standing, presented himself as a candidate for the post. He failed to obtain it, being defeated by Gaspar de Grajal, a future ally and fellow victim:[25] so far as can be ascertained, this was Luis de Leon's sole academic check. Manifestly he was not daunted. He claimed, and established, his right to take part in certain examinations in his faculty,[26] and 'con mucho exceso' thwarted the designs of the famous Domingo Bañez, whom he afterwards described as 'enemigo capital'.[27] His combativeness did him no immediate harm, for, in December 1561, he was elected Professor of Theology at Salamanca.[28] He was obviously not disposed to hide his light under a bushel, nor to perform his academic duties in a spirit of humdrum routine. Whatever he did, he did with all his might, and his strenuous versatility made him conspicuous in University life. In 1565 he was transferred from the theological chair to the chair of Scholastic Theology and Biblical Criticism, in which he succeeded his old master Juan de Guevara.[29]