"The University of Cambridge is a public collegiate research university in Cambridge, England. Founded in 1209, the University of Cambridge is the world's third-oldest university in continuous operation. The university's founding followed the arrival of scholars who left the University of Oxford for Cambridge after a dispute with local townspeople. The two ancient English universities, although sometimes described as rivals, share many common features and are often jointly referred to as Oxbridge. In 1231, 22 years after its founding, the university was recognised with a royal charter, granted by King Henry III. The University of Cambridge includes 31 semi-autonomous constituent colleges and more than 150 academic departments, faculties, and other institutions organised into six schools. The largest department is Cambridge University Press and Assessment, which contains the oldest university press in the world, with ￡1 billion of annual revenue and with 100 million learners. All of the colleges are self-governing institutions within the university, managing their own personnel and policies, and all students are required to have a college affiliation within the university. Undergraduate teaching at Cambridge is centred on weekly small-group supervisions in the colleges with lectures, seminars, laboratory work, and occasionally further supervision provided by the central university faculties and departments. The university operates eight cultural and scientific museums, including the Fitzwilliam Museum and Cambridge University Botanic Garden. Cambridge's 116 libraries hold a total of approximately 16 million books, around 9 million of which are in Cambridge University Library, a legal deposit library and one of the world's largest academic libraries. Among the university's notable alumni are Francis Bacon, Lord Byron, Oliver Cromwell, Charles Darwin, Rajiv Gandhi, John Harvard, Stephen Hawking, John Maynard Keynes, John Milton, Vladimir Nabokov, Jawaharlal Nehru, Isaac Newton, Salman Rushdie, Bertrand Russell, Alan Turing, Ludwig Wittgenstein, William Wordsworth, and 194 Olympic medal-winning athletes. Its alumni, academics, and affiliates have won 126 Nobel Prizes.