![Pope Tawadros II and Pope Francis.](/sites/default/files/styles/large/public/8726173724_ba96d1dcce_z.jpg?itok=vVlBT8-N)
Tawadros II, head of the Coptic Orthodox Church of Egypt, met with Francis, head of the Catholic Church, in May 2013.
![Coptic Orthodox cross.](/sites/default/files/styles/large/public/600px-Coptic_cross.svg_.png?itok=wklTH7wt)
A Coptic Orthodox cross with the text: Jesus Christ, the Son of God
![Coptic altar in a Jerusalem church.](/sites/default/files/styles/large/public/800px-CopticAltar.jpg?itok=0f0QpZ6b)
Coptic altar in a Jerusalem church
![St. Mark Coptic Cathedral.](/sites/default/files/styles/large/public/StMarkCathAlex.jpg?itok=Y6txrbcf)
St. Mark Coptic Cathedral in Alexandria, Egypt
![Pope Tawadros II.](/sites/default/files/styles/large/public/Pope_Theodoros_II_of_Alexandria.jpg?itok=HZHEkd6w)
Pope Tawadros II, current Pope of the Coptic Church
![Pope Shenouda III.](/sites/default/files/styles/large/public/Pope_Shenouda_III_of_Alexandria_by_Chuck_Kennedy_%28Official_White_House_Photostream%29.jpg?itok=NNDRNH1H)
Pope Shenouda III, predecessor of Tawadros II, in 2009. White House photo by Chuck Kennedy
![Martin Luther's 95 Theses.](/sites/default/files/styles/large/public/95Thesen.jpg?itok=s_l-Ialv)
Written in 1517, Martin Luther's 95 Theses marked the second dramatic division of Christianity.
![White smoke emanating from the Sistine Chapel.](/sites/default/files/styles/large/public/Fumo_branco.jpg?itok=B2ZP_oOJ)
White smoke emanating from the Sistine Chapel indicates that the conclave has succeeded at electing a pope.
![Exterior of the Sistine Chapel.](/sites/default/files/styles/large/public/800px-Sixtina.jpg?itok=gOxomC6H)
The unremarkable exterior of the Sistine Chapel, where papal conclaves are held
![Canterbury Cathedral.](/sites/default/files/styles/large/public/Canterbury_Cathedral_-_Portal_Nave_Cross-spire.jpeg.jpeg?itok=m_ZCzEwi)
Canterbury Cathedral, home church of the Archbishop of Canturbury and one of the oldest Christian structures in England
![Archbishop of Canterbury.](/sites/default/files/styles/large/public/8447766900_3161dc9576_z.jpg?itok=_RSEypos)
Justin Welby was named Archbishop of Canterbury in November 2012. © Mazur/catholicnews.org.uk
![Gene Robinson.](/sites/default/files/styles/large/public/Bishop_Gene_Robinson_portrait_2005.png?itok=0_jN7daF)
Gene Robinson, openly gay Episcopal bishop of New Hampshire, whose tenure ended in January 2013
![Peter Akinola.](/sites/default/files/styles/large/public/4820868439_eef80f6929.jpg?itok=YF8DhFwn)
Peter Akinola, archbishop of Nigeria from 2002 to 2010, led a boycott of the Anglican Communion over homosexuality issues.
![Avery Dulles.](/sites/default/files/styles/large/public/220px-Cardinal_dulles.jpg?itok=iKqVW4UP)
Not all cardinals are bishops. American theologian Avery Dulles is one example of this.
![The Coptic Orthodox Hanging Church.](/sites/default/files/styles/large/public/383px-Kairo_Hanging_Church_BW_1.jpg?itok=jQPqsnP1)
The Coptic Orthodox Hanging Church in Cairo dates from the 3rd or 4th Century.
![Pope Francis.](/sites/default/files/styles/large/public/Pope_Francis_in_March_2013.jpg?itok=jrJBMrr9)
Pope Francis, Bishop of Rome, elected March 2013
![Members of a Pentacostal church practice a healing ritual.](/sites/default/files/styles/large/public/Laying_on_of_hands.jpg?itok=ExqE--Gj)
Members of a Pentacostal church practice a healing ritual in Kentucky in the 1940s. National Archives and Records photo by Russell Lee
The interior of a Pentacostal megachurch in Sydney, Australia. Photo by Matt Malone
![Young worshippers at a 2011 Pentecostal Christian gathering.](/sites/default/files/styles/large/public/8024196157_906ae92453_b.jpg?itok=tt_Mm0wI)
Young worshippers at a 2011 Pentecostal Christian gathering in Panama
![St. Peter's Basilica in Vatican City.](/sites/default/files/styles/large/public/StPetersBasilicaEarlyMorning.jpg?itok=nuP_5dE0)
St. Peter's Basilica in Vatican City is the largest church in the world and a symbol of the Catholic Church.
![Pope Benedict XVI.](/sites/default/files/styles/large/public/399px-Papa_Benedetto.jpg?itok=SNgm8myb)
Pope Benedict XVI, now pope emeritus, took the nearly unprecedented step in 2013 of retiring before his death.
![Henry VIII.](/sites/default/files/styles/large/public/427px-Hans_Holbein%2C_the_Younger%2C_Around_1497-1543_-_Portrait_of_Henry_VIII_of_England_-_Google_Art_Project.jpg?itok=DkcN-Wli)
Henry VIII's break with Rome represented the culmination of a long struggle between the papacy and “secular” rulers over control of church offices and properties.