In 1150 the future University of Paris was a student-teacher corporation operating as an annex of the Notre-Dame cathedral school. The earliest historical reference to it is found in Matthew Paris' reference to the studies of his own teacher (an abbot of St. Albans) and his acceptance into "the fellowship of the elect Masters" there in about 1170, and it is known that Lotario dei Conti di Segni, the future Pope Innocent III, completed his studies there in 1182 at the age of 21.