The papal tiara is the crown of the pope. For over a thousand years all popes were crowned with some kind of a tiara in a papal coronation. The tiara is still one of the key symbols of the papacy, and features on the coat of arms of the Holy See and of Vatican City State. Pope Benedict XVI had replaced the tiara on his official coat of arms with a traditional bishop's mitre and the pallium, symbols of the Pontiff's authority as Bishop of Rome.
Though people talk of the tiara, there are in fact over twenty surviving tiaras in existence. The earliest dates from the sixteenth century, the latest from 2016. Eleven of them are held in the Vatican and two are permanently on display in the United States at the National Shrine of the Immaculate Conception in Washington, D.C. and at the Basilica of the Sacred Heart, Indiana at the University of Notre Dame.
The most recently made papal tiara was donated to Pope Francis in 2016.
List of papal tiaras in existence Wikipedia
Note: Because the donation of tiaras was often a private matter not announced by the person making the donation, it is unknown whether any subsequent papal tiaras have been donated. The existence of the Hungarian Tiara, though long rumoured, was only confirmed when images of it were shown in the media.
Pope Paul VI decided not to wear his tiara again in a gesture of humility and put it up for sale with the proceeds to be given to the poor. The bishops of the United States bought it and put it on public display together with a gold lace papal stole of saint John XXIII at the National Basilica of the Immaculate Conception in Washington DC. Paul VI's 1975 Apostolic Constitution, Romano Pontifici Eligendo envisaged that his successor would be crowned. However, Pope John Paul I chose instead a coronation-less papal inauguration. Pope John Paul II's 1996 Apostolic Constitution Universi Dominici Gregis spoke only of an inauguration, without specifying the form it should take.