The Leper Chapel is located in Cambridge, Cambridgeshire. It is known as the Chapel of St. Mary Magdalene and was built in 1125, it is thought to be the oldest surviving building in Cambridge. The Chapel was part of a leprosy hospital and stood on its own on the outskirts of the city.
In 1199 the Chapel was granted a royal permit by King John to hold a three day fair so they could raise money to support the hospital. It wasn't until 1211 that the fair was held on Stourbridge Common in September on the Feast of the Holy Cross.
The fair was immediately popular and became over time the largest Mediaeval fair in Europe. The Chapel prospered and the position of priest at the chapel became sought after. The priest had little to do as the hospital stopped admitting new patients in 1279. The patients at the hospital were sent to a new leper colony near Ely.
The chapel was rebuilt in the 13th century. Parts of the eastern wall are from the original structure but the rest of the chapel was rebuilt.
The chapel failed to escape the dissolution of the monasteries in 1546 and was seized by the crown. The hospital was demolished but the chapel survived. The rights to the fair were fought over by the Universities and the City until Queen Elizabeth I stepped in and ruled in favour of the City but giving the University the rights to control weights, measures and quality of goods. The chapel became a store for the stalls of the fair and a pub while the fair was being held.
The chapel became too small to store everything the fair required and in 1783 it was advertised for sale as a storage shed. It changed hands a few times until bought by Thomas Kerrich in 1816. Thomas restored the chapel and left it to the University.
Sadly the fair was abolished in 1933. The chapel was falling into disrepair so the University gave the chapel to the newly formed Cambridge Preservation Society in 1951. It is now being used for worship as part of the Parish of Christ the Redeemer. The 'Friends of the Leper Chapel' were formed in 1999 to promote use of the chapel for education, cultural events and worship.
While attending Cambridge University in 1665, Isaac Newton visited the Fair where he bought a copy of Euclid's Elements which he used to teach himself mathematics.
He is also believed to have bought some optical instruments including a pair of prisms with which he used to prove that white light could be split in to the colours of the rainbow.