Unfortunately there are no pictures or maps of the City in earliest times. The first picture of London landmarks appeared about 1500 in the frontispiece of a book of poems by Charles, duke of Orleans, during his imprisonment in the Tower. And the earliest map was that done by Ralph Aggas which was published early in Elizabeth’s reign (1558–1603). But we do have a written description, by William Fitz-Stephens, a learned cleric formerly in the service of Thomas a Becket during the reign of Henry II (1154–89). It is from his description that we get our information about churches and the various monastic establishments in medieval London.