Märsɘ’e Hazän was born on 26 March 1899, son of Aläqa Wäldä Qirqos and Wäyzäro Yäsäwa Wärq in Ĝirru, Shoa. His father was an authority on Yared’s music and hymnody which he had studied in Betä Lɘhem of Begemder. Aläqa Walda Qirqos had a strong desire for his child to be a genius and named him Märsɘ’e Hazän after a famous eighteenth-century master. The young Märsɘ’e Hazän lived up to the expectation of his father. He attended traditional school at Entotto, Addis Ababa. At the age of 11 he had mastered the knowledge of qɘne and then began to study New Testament commentary under Mämhɘr Wäldä Giyorgis. He completed his study within three years and then went to Harar, where he studied Patristics.

In 1920 he began his career as a clerk in the palace. In that year an editorial committee was formed with the ultimate goal of publishing biblical and patristic texts with commentaries. The head of the committee was Aläqa Gabrä Madhɘn, deeply versed in Ethiopian literature. Märsɘ’e Hazän was appointed secretary of the committee. He first worked on Arägawi Mänfäsawi with commentary and prepared it for publication. Next was Sirak and the Minor Prophets. Only the first of these two was published.

Blatta Märsɘ’e Hazän was still fostering the idea of studying modern education. He entered Menelik II School, his own preference, with a desire to pursue higher education abroad. But luck did not favour him. He was soon forced to leave the school and stick to his work.
When the first Amharic weekly review, Bɘrhanɘnna Sälam, began publication in 1925 he became assistant editor and served in this capacity for a short time. However, he soon changed profession when Täfäri Mäkonənə School was opened, and he became a teacher of Ge’ez and Amharic there. At that time he prepared the first systematic Amharic Grammar, which has been used for half a century (1925-75) as a standard textbook in both elementary and secondary schools of the country. His deep knowledge of Ge‛ez and his experience in modern English grammar enabled him to introduce new terms and grammatical rules of lasting significance. He also prepared Tɘmhɘrtä hɘşanat(” [Religious] lessons for children”) which was used as a textbook for moral education. At the same time he took private lessons in English and he was able to translate into Amharic a geography book prepared in English by Dr Martin Wärəqənähə.
In 1930 Märsɘ’e Hazän transferred to ǧəǧəga, near Harar, as Director of the newly opened Ras Mäkonənə School. The occasion was appropriate to demonstrate his administrative ability by introducing a highly praised and effective machinery which was rare at that time. It was then that he was recruited as a member of the Boundary Commission, formed to demarcate between British Somaliland and Ethiopia (1931-35). He was present at Walwal when the fateful incident occurred in 1935 between Italy and Ethiopia and kept an accurate record, but this unfortunately is still unpublished.

After the liberation of Ethiopia from the Italian occupation he served in different offices. From 1941 to 1944 he was Judge of the High Court, and from 1944 to 1954 Head of the Imperial Record and Archive Office. During this period he collected and recorded in 74 volumes historical sources of all kinds. His work extended to collecting oral traditions by interviewing old and important personalities, but only a very tiny part of this collection was published during his tenure of this office.
Another major contribution of Blatta Märsɘ’e Hazän was in the field of law. He chaired the drafting committee of Ethiopian codes. He harmonised the customary and old local laws with modern legal concepts and effectively guided the committee to produce new law codes for Ethiopia, the first of their kind in the history of the country.

Parallel to this he had been working in the field of religion. He was appointed chairman of the Amharic Bible Revision Committee, 1947-60. Almost the whole burden of the work fell on his shoulders. Through his hard work and patience he successfully brought the work to an end and the revised Amharic version was published in 1961 and became a landmark in the history of Amharic literature. He played a vital role in the negotiations with the Coptic Church of Alexandria concerning the emancipation of the Church of Ethiopia. The case was ended smoothly in 1951 by the consecration of an Ethiopian Archbishop for the first time in the history of the Church.

In the last years of his career he served in Parliament in various capacities from 1958 to 1970. He was Registrar, Vice President and Acting President of the Upper House (Senate). From 1970 to 1974 he was appointed adviser to the Antiquities Administration. In 1972 Blatta Märsɘ’e Hazän won the Haile Selassie Prize for Amharic literature for his original and outstanding contribution. In 1973 he became a member of the Amharic Language Academy. In 1974 he retired with a pension. On 29 October 1978 he died peacefully after completing his work of the previous day. He is buried at Yäka Abbo Church, Addis Ababa. Blatta Märsɘ’e, Hazän was married and is survived by six children, three boys and three girls.