On 13 November 1964 - at the end of a festive mass with Eastern Church patriarchs and dignitaries - Paul VI laid his tiara, the triple crown of the papacy, on the altar of St Peter's Basilica - as a gift to the poor of the world.
"Viva il papa povero!" - long live the poor Pope - was applauded by those present.
In doing so, Paul VI also renounced an emblem of spiritual and temporal power that no longer seemed in keeping with the times.
But the tiara had by no means disappeared from the public image of the Pope and the Roman Church leadership.
To this day, the official coats of arms of the Vatican State and the Holy See still feature the triple crown above the two crossed keys of St Peter.
And it is omnipresent on stamps and signs, on tickets and stamps, on official letters and documents from the Vatican.
Roman bishops have probably been crowned with a high priestly headdress after their election since the late 4th century, the shape of which is said to go back to an ancient Phrygian cap.
However, they only wore them outside of liturgical celebrations, for example during processions in the city.
However, it is probably a legend that Emperor Constantine personally presented it to Pope Silvester I (314-335) as a sign of the freedom of the Church.
Symbol of the Pope's threefold power
The tiara was intended to symbolise the threefold power of the pontiff.
"Receive the tiara adorned with three crowns and know that you are the father of all princes and kings, the ruler of the world and the representative of our Lord Jesus Christ on earth," said the cardinal deacon to the newly elected pope as he ascended the throne.
The three crown rings stood for the teaching office, the priesthood and the pastoral office of the Pope.
Paul VI was also crowned on 30 June 1963 in St Peter's Square according to this ceremony. He wore the tiara for the first Christmas and Easter blessing "Urbi et orbi" and on the anniversary of his coronation.
However, he then donated the precious jewel (worth around 10,000 dollars), which had been donated to him by the faithful of his former diocese of Milan, to the poor.
The New York Cardinal Francis Spellman endeavoured to obtain the crown; the Pope left it to the Americans as a sign of gratitude for their generous and long-term help for the poor.
The tiara was then displayed in US dioceses for four years - always accompanied by an offering box and an appeal for donations for the poor. This is said to have raised many millions of dollars - allegedly 1.3 billion.
The tiara has been kept in the Marian shrine in Washington since June 1968.
Paul VI's gesture was in keeping with the spirit of the Council, which called for a poor church for the poor.
A church, however, that by no means said goodbye to the world, but instead stood up for more peace and justice, for human dignity and human rights.
Personal decision of Paul VI
"All the material goods of the Church must be at the service of souls, and every splendour must be subordinated to charity", commented the Vatican newspaper "Osservatore Romano" in November 1964.
The gift "shows a way, opens a horizon, of how the Church and her pastors must separate themselves from something that is not necessary for their life, their dignity, their mission, in order to work for the good of mankind".
The Vatican press office made it clear that this was a personal decision by Paul VI that did not bind his successors. There are further crowns in the papal sacristy that could be used in the future.
Paul VI himself seemed undecided until the end. His 1975 conclave order expressly provided for the "coronation" of a new pope. But John Paul I and his successors decided against it.
"It is no longer in keeping with the times to revive a rite that has been regarded (albeit unjustifiably) as a symbol of the temporal power of popes," said John Paul II when he took office in 1978.
However, he retained the tiara as the pontifical emblem in his papal coat of arms.
Only Benedict VI replaced it in his personal coat of arms with the episcopal mitre, as did Pope Francis.