Pius VI was Pope in 1775.

But the Illuminati were oly founded in 1776.


Pius VII took his name from Pius VI, who was basically killed by Napoleon.


Pius VIII took his name from Pius VII, because he admired the latter's long struggle against Napoleon.


Pius IX was a priest during Pius VIII's time, and greatly admired the latter.


Pius X like Pius IX because the latter was pope for 31 years.


Pius XI believed that Pius X was a saint for his struggle against modernist heresies. So he took the same name.


Pius XII was Pius XI's Secretary of State, or Vice-Pope. He was very close to Pius XI and so he took the same name as him.