As Magdalen College celebrates its 550th year, CHRIS KOENIG tells the story of its foundation

Three bishops of Winchester founded colleges at Oxford. They probably had the funds as during the Middle Ages their home city was Europe's richest bishopric. This summer, the second oldest of the three Oxford colleges, Magdalen, will celebrate its 550th anniversary by placing in its grounds a permanent sculpture by Mark Wallinger - the artist who last year won the Turner Prize with State Britain, a recreation of Brian Haw's anti-Iraq War demonstration in Parliament Square.

From its inception the college has been no stranger to controversy. Its founding bishop, William of Wayneflete (1395-1486), was Chancellor of England in 1457 when he closed the old hospital of St John to found Magdalen on the site, apparently helping himself to all its endowments in the process.

The hospital, which is still commemorated each June with a sermon preached from Magdalen's open-air pulpit in St John's Quad on the Sunday nearest to St John the Baptist's day, had existed for more than 250 years before the college's foundation on June 12, 1458.

William of Wayneflete, who also oversaw much of the building of Eton College for Henry VI, borrowed many architectural ideas for Magdalen from those used by his predecessor William of Wykeham, bishop of Winchester at New College in 1379, as indeed did Richard Fox, the last of the episcopal trio from Winchester, at Corpus Christi in 1516.

The chapel at Magdalen was finished in about 1478. It was described by Christopher Hobhouse, in his classic 1939 book, Oxford, as "certainly the most beautiful of all the colleges". Built some 100 years later than the one at New College, the Wykekam plan is evident. There is an ante-chapel set at right angles to the quire and a great east wall, left austerely windowless.

Unfortunately the similarities do not end there. Wyatt destroyed the original roofs in both college chapels and in the 1830s the embellishments at Magdalen's were actually put up for auction in the college stables.

But we must not carp. Damage to the architecture could easily have been much worse. Even the quadrangle only narrowly escaped demolition in the 19th century. Hobhouse recounts how, in 1822, a senior fellow named Dr Ellerton returned from holiday to find workmen busy pulling down its north side for what would now be described as "health and safety" reasons.

Someone had alleged that the structure was dangerous. We have Dr Ellerton to thank for saving the east cloister and rebuilding the north side, though in less picturesque style than the original.

A century before, Magdalen College also had a narrow shave. No less an architect than Nicholas Hawksmoor in 1724 announced that he had plans to rebuild the whole college as the old buildings were "so decrepit".

Quite what happened to Hawksmoor's plans is unclear, but in the 1730s a fellow of the college called Edward Holdsworth drew up some grand, classical plans - and actually completed one wing of his scheme, which still stands on the banks of the Cherwell and is known as the New Building. Magdalen found itself at the centre of national politics in 1686 when James II, who had already managed to install two Catholics as heads of Oxford colleges, took a step too far by trying to foist one on Magdalen.

The presidency of the college was not in his gift and he lost the battle. Some say it was the beginning of the end for him.

As for controversial sculptures, 19th-century students bribed stonemasons to carve one of the beasts in the quad in the likeness of the above-mentioned Dr Ellerton. The joke was that as time went by he began to resemble that creature more and more.