This is the first part of a two-volume edition of the surviving theatrical documents from the archives of the old Madrid hospitals, founders of the capital's playhouses. This book covers the first four decades of the corrales, a key period inwhich the hospitals still administered their theatres directly (and which therefore hardly figures in the municipal documentation published in previous volumes). It includes the original sale contracts of the theatres, from 1579-1582, and the account books for 1579-1587, and indispensable source of information on the acting companies, the construction of the theatres and the early stages of the theatre business in Madrid. The introduction contains a database analysis of the account books, illustrated with graphs and tables, and the volume includes calendars of performances and an index of names and places.