Lay cardinal

Teodolfo Mertel, the last man to have been created cardinal without first having been ordained a deacon. He was ordained to the diaconate in 1858, a few months after becoming a cardinal.

In the historical practice of the Catholic Church, a lay cardinal was a man whom the Pope appointed to the College of Cardinals while still a layman. This appointment carried with it the obligation to be ordained to a clerical order, meaning that "lay cardinal" was not a permanent state, but a term in reference to a man who was appointed cardinal prior to taking on the clerical state corresponding to that appointment.

The current law of the Catholic Church is that a man must be first ordained at least a priest in order to be considered for appointment as a cardinal.