On January 17, 2008, a joint celebration of Divine Liturgy by Oriental Orthodox Churches was held in Montebello. His Eminence Archbishop Hovnan Derderian, Primate of the Western Diocese, accompanied by the Very Rev. Fr. Dajad Dz. V. Yardemian, Vicar General of the Western Diocese, the Very Rev. Fr. Baret Dz. V. Yeretsian, Pastor of St. Gregory the Illuminator of Pasadena, as well as several other clergy including Parish Priests and Deacons, participated in this wonderful and enthusiastic joint celebration of Divine Liturgy.