Apologizing that it was taking him so long, Charles II died on February 6, 1685. He had suffered a fit of apoplexy on February 2 (O.S.) and had asked his brother James the Duke of York to take care of his mistresses (no word about his wife?) and certainly "let not poor Nelly starve."
Before he died Charles' brother and his wife Catherine of Braganza arranged to have the priest Father John Huddleston who had saved him in England after the defeat at Worcester come into the Royal Sickroom. The Bishop of Bath, Thomas Ken (future nonjuror) and all the other Anglicans left the room. The line attributed to James was that the priest who had saved his body was there to help save his soul--and Charles II was received into the Catholic Church and received Holy Communion as Viaticum.
Then when the Bishop and other clergy and nobility came back into the room, Charles did not received Anglican communion. When he was buried at Westminster Abbey on February 14, his funeral ceremonies were rather restrained, possibly by the knowledge that he had "Poped" before he died.
Charles had ruled alone after dissolving Parliament in 1681, the conflict with Parliament, caused at partially (as it had been for his father) by religious matters. After the furor of the Popish Plot he had restored his brother to the position of High Admiral in violation of Parliament's Test Act and he had begun again to rely on France for funds. He might have been heading for another Civil War, but what some have called his love of ease, his laziness, might have pulled him back so he would avoid exile once again. He was not so dedicated to Catholic faith as James, and would have been more politic, just as waiting until at the point of death to convert he delayed his promised conversion.