FTP, name this act which was performed by Sulla, Diocletian, and King Edward VIII.
After performing this act in 1354, John Cantacuzenus changed his name to Joseph Christodulus and wrote a history of the previous 35 years.  A man named Isaac wrote a Scholia on the Iliad at the monastery of Studion after doing it in 1059.  John Casimir became the abbot of Saint-Germain-des-Pr? after doing it in 1668, while Milan Obrenovic also moved to France after doing it in 1889.  It was established as a papal prerogative by Celestine V, though it had been done previously by Benedict IX and Gregory VI.  Some beneficiaries of it include Maria II of Portugal, Charles X of Sweden, and Holy Roman Emperor Ferdinand I.  It was done voluntarily in Rome in 79 BC, and more famously in England in 1936.  FTP, name this act which was performed by Sulla, Diocletian, and King Edward VIII.
After performing this act in 1354, John Cantacuzenus changed his name to Joseph Christodulus and wrote a history of the previous 35 years.  
abdication (accept equivalents)