Maphryono Mor Baselios Yeldo was born at Karakosh near Mosul in Iraq, where Marthsmooni and her 7 children suffered Martyrdom. He become a monk in Mor Bahnan monastery in Mosul. The saint came to India via Basra to Surat, after consecration as Maphrian (Catholicos / Maphryono) by the Patriarch Mor Ignatius Abdul Messiah I, arriving at Thalassery in North Kerala, then by hill route to Kothamangalam in AD 1685 at the request of Marthoma II of Malankara Church. He reached Marthoma Cheriapalli with Mor Ivanios, guided by a Hindu gentleman whose descendants guide the procession of the festival held in his memory every year. The saint expired on October the second and is entombed in the sanctuary of MarThoma CheriaPally, Kothamangalam. In 1987 his name was included in the 5th Tubden (Holy diptych) as per the Patriarchal bull.

                Following the historic synod of Udayamperoor (Diamper) convened in 1599 by a Roman Catholic Archbishop with an intention to enforce the Papal authority over the Malankara Church, the native Jacobite Syrian Christian community had to face severe persecutions by the Portuguese as they preferred to continue within the Holy Apostolic See of Antioch. The situation reached a flash point with the brutal murder of the Patriarch Moran Mor Ignatius Ahathulla by the Portuguese in January 1653. Agitated at this, the Jacobite Syrian Christians numbering about 25000, assembled at Mattancherry (HQ. of Portuguese military) and expressed their strong protest against the Portuguese atrocities and took the historic oath at the 'KOONEN CROSS' , in which they pledged that they and their future generations will never again tolerate the Roman Catholicism that the Portuguese tried to forcibly introduce and also vowed to ever remain loyal to the Holy Apostolic See of Antioch, maintaining their ancient rites and traditions. Later urgent appeals were sent to the then Patriarch of Antioch requesting for immediate help. Learning about the sad situation then prevailing in the Malankara Church, the saintly Mor Gregorios Abdul'Galeel, who was then the Metropolitan of Jerusalem, volunteered to come to Malankara. Though with much difficulty, he was able to reaffirm the Holy faith of the Syrian Christians and also re-established the Episcopacy in Malankara by ordaining MarThoma I and MarThoma II, the first known native Metropolitans. After successfully accomplishing his difficult mission, His Grace died in 1681 and was entombed at the St.Thomas Church, North Paravur.