A Papal Mass is the Solemn Pontifical High Mass celebrated by the Pope. It is celebrated on such occasions as a papal coronation, an ex cathedra pronouncement, the canonization of a saint, on Easter or Christmas or other major feast days.
Pope Benedict XVI photographed during a Papal Mass celebrated in St. Peter's Basilica in 2013
The Elevation during the papal form of solemn pontifical Tridentine high Mass celebrated by Pope John XXIII in St. Peter's Basilica in the early 1960s. Note the mitre and the papal tiaras placed on the high altar. The Greek clergy are standing - as is customary - while the others kneel.
Modern papal Mass in São Paulo, Brazil
A papal coronation is the formal ceremony of the placing of the papal tiara on a newly elected pope. The first recorded papal coronation was of Pope Nicholas I in 858. The most recent was the 1963 coronation of Paul VI, who soon afterwards abandoned the practice of wearing the tiara. To date, none of his successors have used the tiara, and their papal inauguration celebrations have included no coronation ceremony, although any future pope may elect to restore the use of the tiara at any point during his pontificate.
Coronation of Celestine V, the only pope to be crowned twice.
Photograph showing the moment of the coronation of Pope Benedict XV in the Sistine Chapel, 1914 The Humeston New Era (Iowa newspaper)
Procession for the possessio of Pope Benedict XIII
Consecration of Antipope Benedict XIII at Avignon, 28 September 1394