He was born in Addi Nebreid in Northwestern Tigray, and although he completed high school in Adwa. After the Ethiopian revolution broke out, he joined the TPLF. As a commander of EPRDF forces, General Hayelom led his forces to northern Shewa and later marched to Addis Ababa coming out victorious in 1991. One of his most daring acts was the "Agazi Operation", which happened on the early evening of 5 February 1985: he led a squad of TPLF fighters in attacking the main prison in Mek'ele, and freed over a thousand prisoners, killed 16 prison guards and wounded 9 soldiers without losing a single man. He later become one of the military leaders in the defence force of the Transitional Government of Ethiopia.