The official founding of Cambridge University is traced to the enhancement, by a charter in 1231 from King Henry III of England (the first English university to be granted one; Oxford followed in 1248), which awarded the ius non-trahi extra (a right to discipline its own members) plus some exemption from taxes, and a bull in 1233 from Pope Gregory IX that gave graduates from Cambridge the right to teach "everywhere in Christendom".[16]
After Cambridge was described as a studium generale in a letter by Pope Nicholas IV in 1290,[17] and confirmed as such in a bull by Pope John XXII in 1318,[18] it became common for researchers from other European medieval universities to visit Cambridge to study or to give lecture courses.[17