John Syclyng has been supposed to have ruled Christ's College for little more than a year, and in arriving at that conclusion Dr Peile presumably calculates from 1 May 1505. He dates his death 9 June 1507; Masters, ed. Lamb, gives it as 9 June 1509, from which it may be supposed Cooper copies in Athenae, but none supplies his authority. Syclyng was still Master of Christ's in a document bearing the date 28 November 1506, by which all the properties given to the college by the foundress are granted to John Syklyng, Master, and the college. Eleven days later, 9 December 1506, Richard Wyatt is Master and his name appears again 28 January 1507, in a lease of the great orchard, now Fellows' Garden.

It is disappointing not to possess exact knowledge of the date upon which the college suffered the loss by death of this great Master. His will bears the date 24 September 1506 and it was the practice of the great majority of people of his period to make their testaments on the visible approach or threat of death. The important function attending the presentation and acceptance of the statutes was observed ‘in a certain upper chamber of the wise Master John Siclyng Master or Keeper of Christ's College…near the gates in the same place’; and when it is remembered that he was waited upon there by the foundress's representative, the Master of Michaelhouse, by the notary public, and by two independent persons specially called as witnesses to represent the university, it is impossible to resist the conclusion that Syclyng was at that time a very sick man; in any other condition he and his fellows would have been required to wait upon the Master of Michaelhouse as representing the Lady Margaret.