Simon Bache

In the parish church of Knebworth, Herts, is the brass of a priest, with the following inscription:— "Hic jacet Dominus Simo Bache, Clericus, quondam *Thesaurarius Hospitii* illustrissimi Principis Domini Henrici Quinti Regis Angliæ, ac Canonic. Ecclesiæ Cathedralis Sancti Paulli, London; qui obiit xix. die Maii. Anno Dom. nostr. 1414." Can any of your readers inform me what this office of *Thesaurarius Hospitii* was; also, who Simon Bache was that held it; and how it happens that he is buried at Knebworth?