He was born in Târgu Jiu, Gorj County, Kingdom of Romania, and graduated from the Infantry Officer School in 1910 with the rank of 2nd lieutenant.

After Romania entered World War I in August 1916, he fought in the Romanian Campaign and was promoted to captain in November 1916.

On June 22, 1941, Operation Barbarossa (the invasion of the Soviet Union by Nazi Germany and its allies) commenced, with the Mountain Brigade entering Northern Bukovina.

On April 12, 1945, Lascăr became commander of the Horia, Cloșca și Crișan Division; the political commissar attached to this Soviet-organized unit was the Communist activist Valter Roman.

After a coalition led by the Romanian Communist Party won the election (through widespread intimidation tactics and electoral fraud), he was appointed Minister of Defense, holding this ministerial portfolio from November 29, 1946 until December 27, 1947, when he was replaced by Emil Bodnăraș.