Johannes de Sacrobosco or Sacro Bosco (John of Holywood, c. 1195 - c. 1236) was an English scholar and astronomer/astrologer who taught at the University of Paris and wrote the authoritative mediaeval astronomy text "Tractatus de Sphaera". Although described as English, his birthplace is unknown because Sacrobosco is an otherwise unknown town or region. Wikipedia
The definitive Wikipedia entry for Johannes de Sacrobosco. Wikipedia is the biggest multilingual free-content encyclopedia on the Internet. en.wikipedia.org/wiki/Johannes_de_Sacrobosco
