- 20 July 1948: Born in Irbid – Jordan
- 1972 – 1975: Vicar of the parish of Christ the King, in Misdar (Amman),
- 1975 – 1976: Vicar of the parish of Fuheis, Jordan,
- 1976 – 1979: Fidei Donum priest in Dubai, UAE (United Arab Union)
- 1979 – 1981: Vicar in the parish of Christ the King, in Misdar, Amman,
- 1981 – 1988: Parish Priest & Director of Catholic Schools – Madaba (Jordan)1972: BA in Philosophy and Theology – Pontifical Lateran University (Rome)
- 1981 – 1988 Parish Priest & Director of Catholic Schools – Madaba (Jordan)
- 1990: MA in Pastoral Theology – Pontifical Lateran University (Rome)
- 1992: PhD in Pastoral Theology and Catechesis – Pontifical Lateran University (Rome) (Adult Catechesis in the Latin Patriarchate of Jerusalem).
- 1992 – 1994: General Director of Latin Patriarchate Schools in Palestine.
- 1992 – 1998: Teacher at St Cyril Diploma Program – Bethlehem University
- 1992 – 2005: Teacher at the Latin Patriarchate Seminary – Beit Jala
- 1994 – 2005: Rector of the Latin Seminary – Beit Jala
- 1996 – 2004: Teacher at St Paul Seminary (Cremisan) – Beit Jala
- 1998 – 2005: Teacher at Bethlehem University
- 2004 – 2005: Teacher at Saint Saviour Franciscan Seminary (Jerusalem)
- 2005: Bishop of Tunis
- 2010: Archbishop of Tunis
- 2012: Patriarchal Vicar in Jordan
- Feb 4, 2017: the Holy Father has accepted his resignation
- 2017: Retired in Our Lady of Peace Center – Jordan
Bishop Lahham published four pastoral letters:
- One year later (Tunis 2006)
- The role of the laity in the Church (Tunis 2008)
- The Word of God (Tunis 2009)
- “Behold, I make all things new” (Tunis 2011)
He wrote and translated books and articles, and presented conferences on adult catechesis, Christian spirituality, peace in the Holy Land, the significance of Jerusalem for the three monotheistic religions, interreligious dialogue, Lectio Divina, sacraments, Christian anthropology, and history of the Latin Patriarchate.
