Leizer Karpel was born in 1917 in the village of Staraia Rudnia, on the Belorussian-Lithuanian border (now in Belarus). Between 1921 and 1939 this area was part of Poland. In 1925 Leizer's family moved to nearby Smorgon (Smorgonie in Polish), from which his parents had come. In 1939 the area was annexed to the Soviet Union. In May 1941, a month before the German attack on the Soviet Union, Leizer was drafted into the Red Army as a medical orderly. With the beginning of the Soviet-German war, he fought in the area of Smolensk-Viazma (western Russia), where he evacuated dozens of wounded men from the battlefield. The Smolensk Defensive Operation of July-August 1941 was followed by the slow retreat of the Soviets to Moscow. In October 1941 Karpel was captured by the Germans and put into a POW camp near Smolensk. During the transfer of the Soviet POWs from one camp to another, Karpel managed to escape and hide in the villages. A month later the Germans arrested him again and returned him to the camp in the Smolensk area.
To Karpel's good fortune, he was captured in 1941 without documents so he was able to present himself to his captors as a (non-Jewish) Belarusian named Aleksandr Karpov. He remained in the POW camp until August 1943. In that month, fearing a Soviet offensive in the direction of Smolensk, the Germans transferred the prisoners westward, to Belorussia. In September 1943, Karpel escaped again and, two days later, joined some Soviet partisans. Then Leizer revealed his true identity: he declared to the partisans that he was not the Belarusian Aleksandr Karpov but the Jew Leizer Karpel. Since he spoke Belarusian, Russian, German, and Polish (as well as Yiddish and Hebrew) the partisan command made him a scout. A short time later, he became the commander of a reconnaissance platoon.
In June 1944 the area, south of Vilnius, where Karpel's partisan brigade was fighting was recaptured by the Red Army. The partisan brigade was transformed into an army unit, whose task was to cleanse the forest area of the last German soldiers and of the Polish partisans of the Home Army (AK), which regarded this area as still part of Poland and fought against the Red Army. While fighting in his native area, Karpel learned that his parents and sisters had been killed by the Nazis (his brothers had been drafted into the Red Army in 1941). After that Karpel asked to be sent to the front. In the fall 1944 and in 1945, with his 235th Infantry Division, he served in Lithuania, Latvia, and Eastern Prussia – once again as a medical orderly. He participated in combat until May 12, 1945 since even four days after VE-Day there were still some German military units that had not yet laid down their weapons.
Karpel was wounded twice. He was awarded the Order of Red Banner and four medals. His elder brother Ievno (Iona) Karpel (who was born in 1903) was killed during the Red Army storming of Berlin in 1945.
After the war, as a person fluent in Polish, Leizer Karpel continued to serve with the Soviet occupation forces in Silesia, which at this time was transferred from Germany to Poland. He was demobilized in 1947. After marrying, he submitted a request to the Soviet authorities to let him emigrate - to the Land of Israel, but his request was rejected.
In 1958, as a former Polish citizen, Karpel was allowed to repatriate to Poland. In 1959, he immigrated to the State of Israel. There he lived in Hadera, where he died in 2007.
Karpel wrote a brief memoir for the collection Smorgon mehoz Vilno: Sefer edut ve-zikaron (Smorgon, Vilna Region: A Book of Testimony and Memory), Tel-Aviv, 1965.