Trinity has many college societies, including the Trinity Mathematical Society, which is the oldest mathematical university society in the United Kingdom, and the First and Third Trinity Boat Club, its rowing club, which gives its name to the college's May Ball. Along with Christ's, Jesus, King's and St John's colleges, it has also provided several of the well known members of the Apostles, an intellectual secret society. In 1848, Trinity hosted the meeting at which Cambridge undergraduates representing public schools such as Westminster codified the early rules of football, known as the Cambridge Rules. Trinity's sister college in Oxford is Christ Church. Like that college, Trinity has been linked with Westminster School since the school's re-foundation in 1560, and its Master is an "ex officio "governor of the school. Trinity also maintains a significant connection with Whitgift School in Croydon, as John Whitgift, the founder of Whitgift School, was the master of Trinity from 1561 to 1564.