Possibly from uremia. The related link below will explain more.
King Charles II died of a stroke in February 6th 1685
Charles II of Albret died in 1471.
Charles Phelps Taft II died in 1983.
Charles Comiskey II died on August 26, 2007, in Hinsdale, Illinois, USA.
Archduke Charles II of Austria died on July 10, 1590 at the age of 50.
Charles H. Price II died on 2012-01-12.
Charles Ridgely II died in 1772.
Charles II of Albret died in 1471.
Charles Christian II died in 1886.
Charles II of Naples died on 1309-05-05.
Charles II of Navarre died on 1387-01-01.
Charles Scribner II died on 1930-04-19.
Charles Phelps Taft II died in 1983.
Charles Harold Haden II died in 2004.
Charles Comiskey II died on August 26, 2007, in Hinsdale, Illinois, USA.
King Charles II of Spain died on November 1, 1700 at the age of 38.
Archduke Charles II of Austria died on July 10, 1590 at the age of 50.
Charles Shannon II died on December 21, 2003, in Los Angeles, California, USA of complications from a stroke.