Iakov (Iasha) Forzun was born in 1924 in Korostyshev, Ukraine. After graduating from school in 1939, Forzun moved with his mother to Zhitomir, where he worked as a tinsmith. After the outbreak of war between Soviet Union and Nazi Germany on June 22, 1941, Forzun and his mother managed to evacuate to Russia's Penza District, where he worked as a tractor driver on a collective farm (kolkhoz). In August 1942 Iakov Forzun was drafted into the Red Army. After several months of study at the Chapaevsk Infantry School, he was sent to the Briansk Front. He served as a machine-gunner, participating in the battles for Stalingrad and Kursk and was seriously wounded twice. On June 22, 1944 the Red Army launched Operation Bagration (June, 22 - August 19, 1944) for the liberation of Belorussia and eastern Poland. On June 24 as a machine gunner at the Infantry Regiment Forzun participated in an attack on the German front lines north of Vitebsk. Along with several others soldiers Iakov volunteered to be among the first to cross the West Dvina River and to seize a bridgehead on its left bank. After crossing the river undiscovered and reaching the enemy rear, Forzun and his comrades opened fire as a signal to the rest of the troops to cross also the river. However, the next day the Germans launched a deadly offensive, killing the members of his group except for Forzun who, along with several other Red Army soldiers who had joined him, repulsed 11 German attacks, killing several hundred Germans before being united with the rest of the battalion's troops. On July 22, 1944 Forzun was awarded the title of Hero of the Soviet Union for courage displayed during the West Dvina crossing. Forzun was informed about this while recovering in hospital after having been seriously wounded. In a video interview given in 2012 Forzun recalled this moment, stressing that at that time being awarded this medal had a special meaning for him as a Jew:
"… a meeting [in his honor] was held in the hospital hall and all the patients were gathered there. The head of the hospital took [the letter] and read it out before all those gathered; it stated that I had been awarded the title of Hero of the Soviet Union. … Then he told me to deliver a speech. So I delivered a speech, saying that [during the war] I fought … [in many battles], I was the first to cross the West Dvina, holding [there] the defense line... here [in the hospital], all of us [the wounded soldiers] are lying in the same room but some … keep saying that the Jews don't fight. However, I can tell you that I am a Jew and I have deserved the title of Hero of the Soviet Union. I fought well and all the [other] Jews are fighting well. … When I said this, the doctors and the nurses… began to cry… [since] many of these doctors…and the medical personnel were Jews…."
In January 1945 the article “Machine-gunner Iakov Forzun Killed 40 Hitlerites in One Battle. He Was Awarded with Title of Hero of the Soviet Union," by Major Aron Toker, was prepared by the Jewish Anti-Fascist Committee for the Jewish press in the West. In early February Iakov Forzun arrived in Moscow to receive the Hero of the Soviet Union medal. While in Moscow he visited the Jewish Anti-Fascist Committee office and met with its leaders.
In 1946 after demobilization Forzun worked as a foreman in Zhitomir. In 1990 Iakov Forzun immigrated with his family to Israel, where he is now living in the city of Or Akiva.