Church heads and ecumenical leaders from all around the world were among the massive crowd in Rome to attend the inauguration of Pope Francis on Tuesday.

Among the church leaders there were the general secretary of the World Council of Churches, Rev. Olav Fykse Tveit, the Archbishop of York, Rev. John Sentamu representing the Archbishop of Canterbury and the Ecumenical Patriarch of Constantinople Bartholomew I.

At the beginning of his homily, Pope Francis acknowledged the church leaders and thanked them for coming to his inauguration.

"I offer a warm greeting to my brother cardinals and bishops, the priests, deacons, men and women religious, and all the lay faithful.

"I thank the representatives of the other Churches and ecclesial Communities, as well as the representatives of the Jewish community and the other religious communities, for their presence," said the new pontiff.

In a statement, Tveit said he attended the event in order to give a "significant expression of the WCC's collaboration with the Roman Catholic Church, as well as our mutual commitment to church unity and the ecumenical movement."

The WCC brings together some 560 million Christians through the 349 Protestant, Orthodox, Anglican, and other churches in the WCC. The Geneva-based Christian organization promotes Christian unity and has worked with the Roman Catholic Church on matters of faith, witness and the fundamental unity of the whole body of Christ.

The WCC general secretary also assured Pope Francis of prayers and said common prayer is an opportunity to reconfirm that Christians need one another.

"Participating in common prayer to mark the start of Francis's papacy highlights the ecumenical dimension of our shared spiritual life, the heart of what we share as Christians," said Tveit.

Many church leaders also shared in the excitement surrounding Pope Francis' as the first pope from Latin America, the southern hemisphere, the Americas, and the first to choose a name honoring St. Francis of Assisi.

"God is good! I am praying for Pope Francis I. Like St Francis of Assisi, I pray he'll be an instrument of peace and preach the Gospel - use words if he must," said the Archbishop of York who is representing the Anglican Communion and the Church of England.

Usually, it would be the Archbishop of Canterbury who would be the Anglican representative to attend a papal inauguration. But in this case, the Archbishop of Canterbury Justin Welby is preparing for his own enthronement on Thursday.

The inauguration of Pope Francis was also historic because it drew the presence of the Ecumenical Patriarch of Constantinople Bartholomew I, leader of some 300 million Orthodox Christians, to the Vatican.

The gesture is significant because the ecumenical patriarch has not attended the pope's inauguration since the Catholic-Orthodox split in 1054.

The Ecumenical Patriarch said he would pray that the new pope's "tenure may prove to be a source of peace in our world of turmoil and division" and "a continuation of our journey toward reconciliation and consolidation of the dialogue toward unity as Sister Churches."

The Christian delegations will meet the new pontiff during the Papal Audience Ecumenical Meeting on Wednesday.

The full list of Christian delegations who attended Pope Francis' inauguration is:

ORTHODOX

ORIENTAL ORTHODOX

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CHRISTIAN ORGANIZATIONS

OTHER REPRESENTATIVES