He established the doctrine of the immaculate conception at the First Vatican Council.
This man caused controversy when he adopted Edgardo Mortara on the grounds that Edgardo's Jewish parents should not be allowed to care for a baptized child. He listed a number of faulty arguments by citing prior Papal writings that condemned them in his Syllabus of Errors. He established the doctrine of the immaculate conception at the First Vatican Council. For 10 points, name this longest serving pope.
This man caused controversy when he adopted Edgardo Mortara on the grounds that Edgardo's Jewish parents should not be allowed to care for a baptized child.
{Pius IX}