Pope Paul VI was the last pontiff to wear the papal tiara

Papal Tiara

The Papal Tiara is a crown symbolizing the threefold authority of the Supreme Pontiff: Universal Pastor (top), Universal Ecclesiastical Jurisdiction (middle) and Temporal Power (bottom) . Of this last, only the Vatican City State remains from the papal territories, which in past ages secured the autonomy of the Vicar of Christ from the princes of this world.
The triple tiara can also be understood to have a spiritual interpretation, the three-fold office of Christ, Who is Priest, Prophet and King. The Lord communicated these offices to the Apostles, and in a particular way to Peter, so that they could sanctify, teach and govern in His name and by His authority  (
Mt 16:13-18, Mt 18:18, Mt 28:18-20, Lk 22:31-32, John 21:15-17).
Pope Paul VI was the last pontiff to wear the papal tiara. At the end of the Second Vatican Council, Pope Paul VI descended the steps of the papal throne in St. Peter's Basilica and laid the tiara on the altar in a dramatic gesture of humility and as a sign of the renunciation of human glory and power in keeping with the renewed spirit of the Second Vatican Council. This last tiara was then given to benefit the poor, but remains as a symbol in the papal crest.

Matthew 16:13-18 :
When Jesus went into the region of Caesarea Philippi he asked his disciples, "Who do people say that the Son of Man is?" [14] They replied, "Some say John the Baptist, others Elijah, still others Jeremiah or one of the prophets." [15] He said to them, "But who do you say that I am?" [16] Simon Peter said in reply, "You are the Messiah, the Son of the living God." [17] Jesus said to him in reply, "Blessed are you, Simon son of Jonah. For flesh and blood has not revealed this to you, but my heavenly Father. [18] And so I say to you, you are Peter, and upon this rock I will build my church, and the gates of the netherworld shall not prevail against it.

Matthew 18:18:
Amen, I say to you, whatever you bind on earth shall be bound in heaven, and whatever you loose on earth shall be loosed in heaven.

Matthew 28:18-20 :
Then Jesus approached and said to them, "All power in heaven and on earth has been given to me. [19] Go, therefore, and make disciples of all nations, baptizing them in the name of the Father, and of the Son, and of the holy Spirit, [20] teaching them to observe all that I have commanded you. And behold, I am with you always, until the end of the age."

Luke 22:31-32 :
"Simon, Simon, behold Satan has demanded to sift all of you like wheat, [32] but I have prayed that your own faith may not fail; and once you have turned back, you must strengthen your brothers."

John 21:15-17 : 
When they had finished breakfast, Jesus said to Simon Peter, "Simon, son of John, do you love me more than these?" He said to him, "Yes, Lord, you know that I love you." He said to him, "Feed my lambs." [16] He then said to him a second time, "Simon, son of John, do you love me?" He said to him, "Yes, Lord, you know that I love you." He said to him, "Tend my sheep." [17] He said to him the third time, "Simon, son of John, do you love me?" Peter was distressed that he had said to him a third time, "Do you love me?" and he said to him, "Lord, you know everything; you know that I love you." (Jesus) said to him, "Feed my sheep."