The Cambridge Union Society, also known as the Cambridge Union, is a historic debating and free speech society in Cambridge, England, the largest society in the University of Cambridge, and a registered educational charity. The society was founded in 1815 making it the oldest continuously running debating society in the world. Additionally, the Cambridge Union has served as a model for the foundation of similar societies at several other prominent universities, including the Oxford Union and the Yale Political Union. The Union's membership is open to all students of Cambridge University and Anglia Ruskin University, as well as members of the public. Alumni of both universities in addition to present and former staff are also permitted to join. The Cambridge Union is a registered charity and is completely separate from the Cambridge University Students' Union.