Emilio Mar Antonio was born on 11 December 1903 in Bambang, Bulacan. He died on 13 May 1967 in Quiapo, Manila. He was a poet and a fictionist. In 1941, he married Andrea Teodoro and they had six children, one of whom is poet Teo Antonio. He was the administrator and mediator of the balagtasan on radio sponsored by Compania Elizalde and wrote for their newspaper, Taliba. He was a member of the editorial board of Liwayway from 1946- 1949 and editor of Bulaklak from 1950-1965.
He wrote three novels in verse: Lakandupil, Nakaluping Dahon and Perlas sa Putikan. He wrote Magat, Ama ng Lahing Kayumanggi, a novel, in prose with Macario Pineda as co-atuhor. They were all published in Liwayway. His Birang na May Luha was published in 1949.
He became popular as a balagtasan poet, who engaged Florentino Collantes, Nemesio Caravana, and others in public debates in verse on contemporary issues. His lyric poems Ang Nayon ko and Gagamba at Alitaptap have been anthologized in Walong Dekada ng Makabagong Tulang Pilipino, 1981.
In 1937, Mar Antonio won a gold medal in the annual choice by the Kapisanang Ilaw ng Bayan in Bulacan for his poem, “Ang Nayon Ko.” He was proclaimed poet laureate by the Kapisanang Diwang Ginto for his poem, “Ilaw.”, and by Liwayway in 1938. He also won in the first balagtasan to be aired on radio besting opponents Fernando Monleon and Francisco Paño. The topic was Sino ang Higit na Dapat Mahalin: Ina, Asawa o Anak?
In 1951, he was proclaimed “Prince of Balagtasan” by the Kapisanan ng mga Makata at Mambibigkas, along with Collantes as the “King of Balagtasan” after a heated poetic joust on the topic: Dapat bang Pairalin ang Import Control sa Pilipinas?
After Collantes’ death in 1954, Antonio and Caravana fought over the coveted title in a poetic joust on the topic, Alin ang lalong Mahalaga: Buhay Kahapon o Buhay Ngayon? He defended Antonio and he was crowned as “King of Balagtasan” by the Taliba ng Inang Wika or TANIW headed by Lope K. Santos.