Delegation of the Armenian Apostolic Church will depart for Vatican on April 23 to take part in the Mass for the solemn inauguration of pontificate Benedict XVI to be celebrated at St. Peter's on Sunday, April 24 at 10 a.m. The delegation is composed of Armenian Patriarch of Constantinople, Archbishop Mesrop Mutafyan, Archbishop Nerses Pozapalyan from Holy Echmiadzin and priest Trdat Uzunyan. It is already known that German President Horst Keller and Chancellor Gerhard Schroeder with their wives will also be present at the solemn ceremony, IA Regnum reports.