Grigory Bruk was born in 1922 in the town of Gradizhsk near Kremenchug, Ukraine. Several years later, the Bruk family moved to Kherson, where Grigory began to attend school.
In 1939, after completing ten years of schooling, Grigory began to attend the Dnepropetrovsk Chemical Technological Institute (the present-day Ukrainian State Chemical Technological University).
Following the outbreak of the Soviet-German War in late June 1941, the nineteen-year-old Grigory Bruk, as a student at the Chemical Technological Institute, was granted an exemption from the draft. Nevertheless, he insisted on enlisting. For this reason, he was sent to the Dnepropetrovsk Artillery School even before the end of June. Almost immediately afterward, the School cadets were dispatched to the frontline Zaporozhe region, despite having received virtually no training. At the age of twenty, Lieutenant Bruk was appointed commander of a food supply platoon. Because of his young age and genteel manners, he initially found it difficult to order about people twice his age. However, after the first few battles he began to get along with them.
In July 1942, the division in which Bruk served was sent to the Rzhev area, which was the site of heavy battles. In January 1943, he was redeployed to the Donbas region, where his division suffered crippling casualties, and was eventually encircled. Bruk was miraculously able to survive these bloody battles. Once, he found himself surrounded, weaponless, in an open area. The Germans began to chase him in a tank for sport, but he fell into a ditch, and this saved his life.
Grigory took part in many battles, disabling several enemy tanks and being wounded. With his division, he advanced through the territory of Hungary, Romania, and Austria. Bruk was awarded the Order of the Patriotic War, 1st class; three Orders of the Red Star; the Order of Alexander Nevsky, and some medals.
Grigory Bruk's parents, who had stayed behind in occupied Kherson, were shot by the Nazis in late September 1941.
After the end of the war, Grigory Bruk remained in the army. In 1956, he completed the higher artillery courses in Leningrad. He was then promoted to lieutenant colonel, and went on to command an artillery battalion in remote garrisons in the USSR.
In 1961, the Soviet Army was reorganized and scaled back. As part of this reform, Grigory was given the option of either retiring from active service or taking the exams for a full course of study at the artillery school (because his wartime studies at the school were no longer regarded as "study" by this point). Grigory Bruk chose the first option, and retired at the age of thirty-nine.