The first European medieval institutions generally considered to be universities were established in Italy, France and England in the late 11th and the 12th Century for the study of arts, law, medicine, and theology. These universities evolved from much older schools and monasteries, and it is difficult to define the first date at which they became true universities for teaching higher education, although the lists of studia generali for higher education in Europe held by the Vatican are a useful guide. Some other institutions such as the imperial university of Constantinople claim that they changed from schools to universities as early as the 11th Century.