The number of students in the school of the capital grew constantly, so that lodgings were insufficient. French students included princes of the blood, sons of the nobility, and ranking gentry. The courses at Paris were considered so necessary as a completion of studies that many foreigners flocked to them. Popes Celestine II, Adrian IV and Innocent III studied at Paris, and Alexander III sent his nephews there. Noted German and English students included Otto of Freisingen, Cardinal Conrad, Archbishop of Mainz, St. Thomas of Canterbury, and John of Salisbury; while Ste-Geneviève became practically the seminary for Denmark. The chroniclers of the time called Paris the city of letters par excellence, placing it above Athens, Alexandria, Rome, and other cities: "At that time, there flourished at Paris philosophy and all branches of learning, and there the seven arts were studied and held in such esteem as they never were at Athens, Egypt, Rome, or elsewhere in the world." ("Les gestes de Philippe-Auguste"). Poets extolled the university in their verses, comparing it to all that was greatest, noblest, and most valuable in the world.