Jacob Melzer was born in 1922 in Czernowitz, in Romania (now Chernivtsi, in Ukraine) as the sixth of the seven sons into a large Jewish family. Before World War I, when the province of Bukovina was part of Austria-Hungary, Jacob's father Wolf was the manager of a large agricultural estate, located 50 kilometers from Czernowitz. After the war, when Bukovina was annexed to the Kingdom of Romania, the new authorities confiscated the land of the Jewish estate owner. Wolf had to move to a suburb of Czernowitz, where he became a farmer. The interwar period was a time of steady economic decline for the Melzer family. In 1940, Bukovina was annexed to the Soviet Union and became part of Soviet Ukraine.
With the beginning of the German-Soviet war in June 1941, two of the Melzer brothers, Shiko and Joseph, were drafted into the Red Army. Miliu, who was a member of the Komsomol (Young Communist League), was evacuated from the city and later conscripted. At that time two other Melzer brothers, Max and Emil, lived in Palestine. Thus, only Iancu (Jacob) and his 15-year-old brother Carl remained at home with their parents when Czernowitz was recaptured by Romania.
In October 1941, four members of the Melzer family, together with the other Jews of Czernowitz, were deported to Transnistria. This was the new Romanian province, which was cobbled together from the left-bank Moldova (this area on the left bank of the Dniester River had never been part of the Kingdom of Romania) and Ukrainian territories located between the Dniester and Southern Bug Rivers. First, along with other deportees, the Melzers were forced into the ghetto of Mogiliov-Podolskii (now Mohyliv-Podilskyi, Ukraine), then they were transferred to the ghetto of Zhmerinka. Iancu's father was sent to a forced labor camp, where he was killed in February 1942.
Iancu, Carl, and their mother were liberated by the Red Army in March 1944. On the fourth day after liberation, Iancu went to the newly opened recruitment office in Zhmerinka and volunteered to join the Red Army. He considered it his duty to fight fascists, regardless of whether they were Romanian or German. "My first spark of an idea when I was embracing a Red soldier, the thought that solidified into a clear understanding, was that just as they had liberated us, I had to go and liberate many of those who were waiting for this," Melzer recalled.
Together with other conscripts, all of whom were Ukrainians, Iancu was transferred to a training camp in the town of Kamenets-Podolskii (now Kam'ianets-Podilskyi, Ukraine). Melzer noted, that both the weapons and the two-week long training were totally inadequate for the war that was going on. Once every two days, after a festive ceremony with an orchestra and officers' speeches, a new battalion that had been formed from the graduates of the "course" left the camp for the front. In a short time word came back that most of the young conscripts had been killed on the first or second day on the front lines: they were poorly trained. That was how the Soviet regime cynically, without regard for human life, punished Ukrainians for the long period they had been under enemy occupation. In this context Melzer's desire to fight waned. "I felt that I was trapped" Melzer recalled. It was clear to him that, regardless of the fact that he had been imprisoned in two ghettos, the Soviet regime regarded him as a Ukrainian and, therefore, was prepared to punish him.
Melzer was prepared for the same kind of death that befell the previous graduates of the training camp, but suddenly, this process came to an end. The conscripts were ordered to return their weapons and to go home and wait for the next draft. They were allowed to keep their uniforms. Iancu returned to Zhmerinka, no longer having any desire to volunteer for the Red Army. Ten days later, both Iancu and Carl received call up orders and assignments to an engineering unit engaged in constructing airfields near the front lines. The unit was sent on foot to the vicinity of Vinnitsa. Iancu recalled having to perform physical labor, without any machines, seven days a week, from dawn to dark. However, within a short time, Iancu and Carl, the only Jews in the "engineering" battalion, but also the only men with some education, were transferred to office work. Carl worked as a draftsman, and Iancu – first as in some supervisory capacity, and then as a land surveyor. After the airfield in the Vinnitsa area was finished, the battalion was transferred to another location.
In 1945, both before and after VE-Day, Iancu served as a military courier. The area where he was serving was particularly dangerous in view of the presence of units of the nationalist Ukrainian Insurgent Army (UPA). Sometimes they stopped and killed Soviet soldiers. Once Iancu's car was also stopped by the "Banderovtsy", as the members of the UPA were referred to. They did not kill him since the other courier spoke Ukrainian, but they took all the fuel and oil from the car.
In December 1945, Iancu was released from the Red Army. In March 1942, Melzer, his mother and brother Carl "repatriated" to Romania and then crossed the border to Yugoslavia. In July 1946, they arrived in Palestine in the framework of Aliya-Bet, the illegal Jewish immigration to the country. He took part in the Israeli War of Independence (a.k.a. the First Israeli–Arab War), when he was wounded, as well as in the wars of 1956, 1967, and 1973. He married and had two children and five grandchildren. Jacob Melzer viewed his life and activity in Israel as his response to the Holocaust.
Jacob's brothers Joseph and Miliu were killed fighting in the ranks of the Red Army. His brother Shiko was injured. After the war, he settled in Siberia, where he died.