Pope Tawadros cried as he assumed the leadership of the Egyptian Coptic Orthodox Church on Sunday morning at the St. Mark Cathedral in Abbasiya in Cairo.
The new pope will lead the church, which claims more than 10 million congregants, succeeding late pope Shenouda III who passed away last March after leading the church for four decades.
Pope Tawadros was chosen from among three religious leaders in an altar lottery on 4 November to head the church.
Hundreds of Egyptian Christians and tens of state officials and international dignitaries packed the Cathedral to mark the historic event.
"He will pray for the entire leadership and will obey the words of God, " the church's officials welcomed the new pope at the helm of the cathedral.
The Church had decided to limit the pope's inauguration to religious rites in mourning of the victims of a train accident that claimed the lives of tens of children in Assiut on Saturday.
President Mohamed Morsi did not attend the celebration sending presidential representatives to take part.
Prime Minister Hisham Qandil attended the ceremony but arrived two hours into the event that started at 8am.
Reform campaigner Mohamed ElBaradei, former presidential candidate Amr Moussa, former MP Marianne Malak were among those who attended.
The ceremony was conducted in Coptic, Arabic, English and French.