CCCC MS 21 contains a high quality copy of Polychronicon by Ranulf Higden (d. 1364) with a continuation to 1377, and was copied shortly after that date. A note in a fifteenth-century hand records that the manuscript was given by 'Henry Somer' to the Hospital of St John the Evangelist in Cambridge. It is sometimes assumed that this is the same man who is described as a Fellow of King's Hall in the early fifteenth century. However, a case can be made for the donor to have been another Henry Somer, a senior royal official who rose to be Chancellor of the Exchequer (1410-39) before his death in 1450, and who expressed a desire to be buried at St John's Hospital. The book passed into the possession of the newly founded St John's College in 1511, since another scribble records the name of 'Shorton', presumably Robert Shorton, the first Master of St John's but later Parker's predecessor as Dean of Stoke by Clare College (1529-35). A sixteenth-century note adds that Somer was involved in a dispute with Corpus Christi over tithes due in Grantchester. It is to be wondered how this 'Inimicus Collegio Corporis Christi Cantabrigiae' might view the acquisition of one of his books by the college.