Pope Martin V - Note On Numbering

Note On Numbering

When the second Pope to take the name Martin was elected, there was confusion over how many Popes had taken the name before. It was believed then that there were three, so the second Pope named Martin was named Martin IV. But, in reality, those believed to be Martin II and Martin III were actually named Marinus I and Marinus II, although they are sometimes still referred to as "Martin II" and "Martin III". This has advanced the numbering of all subsequent Popes Martin by two. Popes Martin IV–V were actually the second and third popes by that name.