Richard of Wallingford (1292–1336) was an English mathematician, astronomer, horologist, and cleric who made major contributions to astronomy and horology while serving as abbot of St Albans Abbey in Hertfordshire. Richard was born, the son of a blacksmith, at Wallingford in Berkshire (now Oxfordshire) in England in 1292. When he was orphaned he was taken to William de Kirkeby the Prior of Wallingford Priory and dedicated to the Holy Trinity. (Wallingford was a dependant priory to S Albans Abbey) Richard subsequently spent six years studying at Oxford University before becoming a monk at St Albans. He later studied for nine more years at Oxford. In 1327 he became abbot of St Albans. Richard of Wallingford is best known for the astronomical clock he designed, while he was abbot, which is described in the Tractatus Horologii Astronomici (1327). The clock was completed about 20 years after Richard's death by William of Walsham but was apparently destroyed during Henry VIII's reformation and the dissolution of St Albans Abbey in 1539. His clock almost certainly was the most complex clock mechanism in existence at the time in the British Isles, and one of the most sophisticated ones anywhere. The only other clocklike mechanism of comparable complexity that is documented in the 14th century is the astrarium by Giovanni de Dondi. Richard’s clock gave the mean time in equal and unequal hours, as well as the true solar time. It also displayed the phases of the moon and showed the positions of the lunar nodes and the height of tide at London Bridge. Based on the 14th-century literary evidence still surviving in the 20th century, several scholars of horological history have tried to build recreations of Richard of Wallingford's clock. The best known of these was built by Haward Horological and for many years was displayed at the Time Museum (now defunct) in Rockford, Illinois; it is currently on display at the Halim Time and Glass Museum in Evanston, Illinois.