Today we celebrate the chair of St. Peter an important feast in the Catholic Church. Here is a beautiful piece by Palestrina related to today’s feast. Tu es Petrus.
Why does St. Peter’s chair matter.
The word chair only shows up three times in the scripture. One of those instances is Matthew 23:2 where Jesus says the Pharisees sit on the Chair of Moses. It represented power however Jesus used it to criticize the Pharisees who put down laws they didn’t follow themselves. However, the seat of the leader represents his power, his authority. The Chair of St. Peter is another way to say that Authority of St. Peter and that of the Pope who are successors of St. Peter.
Where is his Chair?
There are actually multiple answers to this question. First, there is a traditional chair that is believed to be the literal chair of St. Peter. See picture below.

Secondly, the chair of St. Peter more accurately has nothing to do with a chair or throne St. Peter actually sat in, but rather the chair of the successor of St. Peter, Pope Francis. Surprisingly this chair is not in St. Peter’s Basilica in Rome and not even in Vatican City. It is rather down the road in the city of Rome at St. John Lateran. This is the short form of the full Churches name. Cathedral of the Most Holy Savior and of Saints John the Baptist and the Evangelist in the Lateran. In this Church set off by itself is Pope Francis’ chair or cathedra in Latin. See picture below.

Every cathedral in the world has a chair similar to this. I remember being at the rehearsal for the new Bishop. I was assigned as one of the Deacons of the Altar meaning I sat next to the cathedra. During the rehearsal, not realizing what I was suggesting, I told the bishop “you can take a seat.” He was standing in front of the cathedra. Then I realized too late that the Bishop couldn’t sit down yet because he wasn’t fully the Bishop of Baton Rouge.
The Chair of St. Peter is not just a chair for the Pope to sit in, rather it represents the authority of the Vicar of Christ on earth the Supreme Pontiff. This can be seen when a Saint is canonized. While it isn’t done from the actual chair in St. John Lateran it is done sitting on a Cathedra. For example the canonization of Saints John XXIII and St. John Paul II.
The Pope is sitting when he makes this deceleration of the saints he is sitting. A note: the Pope says we declare and define may suggest the Pope makes this statement infallibly. However, if the Pope just said in a homily standing at a random place with a random phrase that Pope John XXIII and John Paul II are now saints it wouldn’t stick. Him sitting and the phrase he used was necessary to canonize them. This is because of the authority of the chair of St. Peter.
A final note a prayer for the Church prayed many times for important feasts like today. This song is heard in the Vatican on occasion.