Neither the Charter of 1858, nor the subsequent Charter of 1863, nor the Supplemental Charters of 1867 and 1878, changed the overall size of the governing body, the Senate, which had been fixed in the original version, in 1836. Its formal composition continued to be a Chancellor and Vice-Chancellor plus thirty-six Fellows. The Chancellor and the Fellows were appointed by the Crown and held office during good behaviour: the Vice-Chancellor was elected by the Senate from amongst the Fellows, and was subject to annual re-election. However, from 1858 onwards, while all Fellows continued to be appointed by the Crown, the practice began of filling a proportion of vacancies from among persons elected by Convocation. Every other new Fellow appointed after April, 1858, was to be chosen, by the Crown, from three elected nominees of Convocation, until a quarter of the Fellowship – nine Fellows – consisted of Convocation nominees – a quota reached in 1866. Thereafter the elective device was employed to fill one vacancy in four. In what follows, the Fellows appointed after nomination and election by Convocation are described as ‘Convocation-nominated’. Those Fellows appointed directly by the Crown are described as ‘Crown-chosen’.

As significant as the formal change which brought Convocation nominees on to the Senate was the change in the attitude of Governments, after 1858, to the matter of filling vacancies. For the first two decades of its existence, the Senate had often been well below its full strength. Deaths and retirements reduced the Fellowship by almost a third in the 1840s. The Conservative Government of Sir Robert Peel, from 1841 to 1846, and Lord Derby’s two short-lived Conservative Governments in the 1850s, made no appointments. But in Lord John Russell’s Administration, six new members were added in 1849–50; and in Lord Palmerston’s first spell in Downing Street a new Chancellor and six new Fellows were appointed in 1856–57. Among the latter were the first two London graduates to enter the Senate – Frederick John Wood and William Withey Gull. Just before the 1858 Charter came into effect, they were joined by Charles James Foster, one of the leaders of the graduates, who was to be the first Chairman of Convocation.