On 26 April 1773, Pope Clement XIV created as many as eleven cardinals in pectore or in the breast. None of the names of these cardinals was ever published. Though there is some speculation that Hyacinthe Cardinal Sigismond Gerdil, C.R.S.P. who would later be named a cardinal under Pope Pius VI was one of them.

The first Pope to appoint a cardinal in pectore was Pope Paul III. Other popes would follow this example throughout history. Pope John Paul II. A pope would chose to create a cardinal in pectore or secret if he believed that publicly naming the cardinal would threaten the cardinal’s life or the faithful in the country where the cardinal lived. For example, in the 20th century popes would create cardinals in Eastern Europe in pectore out of concern over a hostile communist response.

A cardinal created in pectore has no rights as a cardinal until his name has been publicly published and if the pope who named him cardinal dies before having declared their name their status as a cardinal comes to an end as well. However, when a cardinal created in pectore is named, his seniority in the College of Cardinals is dated from the time when he had been created in pectore, not from the time he was publicly named.

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