St John's was founded in 1511. Its foundation charter, dated 9 April that year, was sealed by the executors of the foundress, Lady Margaret Beaufort mother of King Henry VII, who had died in 1509. She had begun the process of transforming the ancient hospital of St John the Evangelist, Cambridge (founded c. 1200), into a college for students in the liberal arts and theology. From a small nucleus of fellows and scholars subsisting in First Court (1511-16) on the College's endowments the numbers grew by 1545 to one hundred and fifty-two. Subsequently the admission of more undergraduates paying for their own board and tuition created pressure on existing accommodation. This led eventually to the building of Second Court 1599-1601, the first major expansion of the College. Other landmarks were the endowment of a new Library building by John Williams, Bishop of Lincoln and Keeper of the Great Seal to Charles I, in 1624-8, strikingly enlarged and complemented by a modern technically-enhanced extension in 1990-3; the bridging of the river and building of New Court 1826-31; the great chapel, designed by George Gilbert Scott, in 1863-9; and the provision of extensive undergraduate accommodation in the Cripps Building, straddling Bin Brook, in 1964-7.
Successive codes of statutes for the government of the College made by John Fisher, Bishop of Rochester and executor of the Foundress, between 1516 and 1530 were superseded by those given by the Crown in 1545 and 1580, until the nineteenth-century Royal Commissions ushered in a period of frequent reform and reorganization. The College is now governed by statutes made in 1926-7, under powers given to the Universities Commission in 1923, as amended by the Governing Body of the College and approved by the Privy Council, and as recently modified by Order of the University Commissioners in 1995.
Because Margaret Beaufort had just "begun the process of transforming the ancient hospital of St. John the Evangelist", Bishop John Fisher had to complete the process, gaining approvals from Henry VIII (who wanted the money), the Pope, and the Bishop of Ely. Beaufort had died in 1509 after serving briefly as Henry VIII's regent before he turned 18 (the son, Henry VII, predeceased the mother).
In his biography of St. John Fisher, Vincent McNabb OP describes how the bishop deeded his library to the College of St. John, with the proviso he should use them during his lifetime. After his arrest, however, one of Thomas Cromwell's men, Sir Richard Morrison went to Rochester and seized all of the poor bishops goods, including his fine library--so St. John's did not receive the books as promised.
The College of St John's honors its foundress in its grace after meals:
Infunde, quaesumus, Domine Deus, gratiam tuam in mentes nostras, ut his donis datis a Margareta Fundatrice nostra aliisque Benefactoribus ad tuam gloriam utamur; et cum omnibus qui in fide Christi decesserunt ad caelestem vitam resurgamus, per Jesum Christum Dominum nostrum. Deus pro sua infinita clementia Ecclesiae suae pacem et unitatem concedat, augustissimam Reginam nostram Elizabetham conservet, et pacem universo Regno et omnibus Christianis largiatur.(Pour forth, we beseech thee, Lord God, thy grace into our minds, that we may use these gifts, given by Margaret our Foundress and other Benefactors, to thy glory, and together with all who have died in the faith of Christ rise again to life in heaven, through Jesus Christ our Lord. May God, of his infinite mercy, grant his Church unity and peace, preserve our most august queen, Queen Elizabeth, and grant peace to the whole Realm and to all Christians.)
It's too bad it doesn't mention the great bishop and founder, St. John Fisher! The college does display his portrait next to Lady Margaret's, and unfortunately also displays some errors in the on-line biography. (He was not canonized by Pope Leo XIII; he was executed on June 22, 1535, etc).