Emilii Mazin was born in 1918 in Rostov-on-Don. His father Zelman (in most of the official documents, Zelman's sons gave his first name as Aleksandr) died in 1926, and the family was provided for by Emilii's older brother Grigorii, who went to work at a factory. While Zelman-Aleksandr was alive, the family observed some Jewish traditions, celebrated holidays, etc. After the father's death, life became hard, and the traditions were abandoned. Emilii described himself as an outright atheist. In 1936, Emilii finished school and enrolled in the Faculty of Physics and Mathematics of the Rostov-on-Don State University, from which he graduated in 1941. One of his fellow students there was Aleksandr Solzhenitsyn, and Emilii would remain friends with the celebrated Russian author for the rest of his life.
In June 1941, the Soviet-German War broke out, and Emilii volunteered to serve in the Red Army. Since he had had no previous military training, he was most probably assigned to the civil militia [narodnoie opolchenie]. Documents on his service in 1941 are missing, and the testimonies of eyewitnesses are contradictory. Be that as it may, by 1942 Emilii had been evacuated to Kazakhstan. From there, he was drafted into the Red Army and sent to a school for commanders of machine-gun platoons. In November 1942, at the peak of the Stalingrad operation, Lieutenant Mazin was sent to the Voronezh Front and appointed the commander of a platoon of 76-mm cannons of the 262nd Rifle Regiment, the 184th Rifle Division. From this point on, Emilii served in the artillery. At some periods, he commanded an ammunition supply platoon for 76-mm cannons; at other times, he himself was a gunner, commanding an artillery company. With his regiment, Emilii traveled through western Russia (the Smolensk Region), Belorussia, and Lithuania, meeting V-E Day in East Prussia. Afterward, he was transferred to the Soviet Far East to fight against Japan in a similar capacity – as the commander of a 45-mm cannons company.
In the course of the war, Emilii Mazin was awarded two Orders of the Red Star and the Order of the Patriotic War, 2nd class. He also received some medals. Mazin was wounded four times, and he returned to Rostov as a disabled veteran: he had lost the vision in one eye, and the hearing in one ear. In 1990, he underwent surgery in his blind eye, and his vision was restored.
After the war, Emilii Mazin worked as a teacher of mathematics. He taught at various schools for 70 years, and at Rostov University for 8 years. He died in 2015.
Emilii's older brother, Grigorii Mazin, also fought in the Soviet-German War, serving in the engineering forces. He finished the war in the rank of colonel. Another brother of his, Mikhail, took part in the war as a military topographer.