Gavriel Maksumov (in his wartime military documents his first name was given as Grigorii) was born in 1915 in Samarkand, Uzbekistan, into a family of Bukhara Jews. Orphaned in his early childhood, together with his four sisters, he was raised by his mother Rakhel. Before the war, Gavriel worked in the book trade, his last job being the manager of a bookshop at the railway station of the city of Kokand, in eastern Uzbekistan.
Maksumov was drafted into the Red Army in 1940; he served at the 184th Separate Communications Battalion in Western Ukraine that had just been annexed to the Soviet Union (before September 1939 it was eastern Poland). He was in Western Ukraine at the time of the invasion by Nazi Germany of the Soviet Union. His battalion was subordinate to the South-Western Front of the Red Army. This Front was decimated during the attempts to defend Kiev and Kharkov, in Eastern Ukraine, in the fall of 1941.
Maksumov's family received his last letter from the front in October 1941. Since his unit was encircled by the enemy from December 1941 to May 1942, there was no possibility of his sending mail to them then. According to his family (his nephews), who tried to ascertain his fate in the 1960s and 1970s, either in December 1941 or at the beginning 1942, Private Maksumov was captured by the Germans. He tried to present himself as a Tajik, but was denounced as a Jew and killed by the Germans.
His mother received an official notification that her son Gavriel was missing in action.
 See: David Kalontarov, Pamiat' i podvig: Imena i sud'by 2727 frontovikov bukharskikh ievreiev, 2nd edition, 2010, p. 131.