9 However, it was divine foresight that Cyril should die on February 14, 869, more mature in virtue than in age. After a splendid public funeral like that given to popes, he was buried with honors in a tomb which Adrian had built for himself. Because the Roman people could not bear to send the holy corpse to Constantinople though his grieving parent asked for it, it was brought to the basilica of St. Clement and buried near him whom Cyril had held in reverence for so many years. As he was taken through the city among festal songs and psalms - not so much in the manner of a funeral as that of a triumph - the Roman people made offerings of heavenly honor to the holy man.
Source: Grande Munus (Vatican.va)