The University of London is a federation of colleges which together constitute one of the world's largest universities. Approximately 5 percent of all UK students attend one of its colleges, which include some of the most prestigious places of study in the world. Many universities in Britain and abroad began life as associate colleges of the university, offering its degrees under licence. The main offices of the University of London are at Senate House in Bloomsbury, which includes a substantial library and the residence of the Chancellor.