The title of the Papal Bull
published by Pope Pius V
on February 25, 1570
, excommunicating Queen Elizabeth I
England and dispensing all her subjects of their oath of allegiance to her. "Regnans in Excelsis" translates as "Reigning in the highest."
Although the bull was issued too late to have actually caused the Northern Rebellion of 1569, the two events were nevertheless linked in Elizabeth's mind. She would henceforth consider all Catholics traitors.