Gichon was born
Mordechai Gicherman in
Berlin,
Germany, to a Jewish family. In 1934, the family moved to
Mandatory Palestine and settled in
Tel Aviv, where his father Nachum ran a German-language newspaper. Gichon was educated at the Ben-Yehuda Gymnasium, and later at the
Hebrew University of Jerusalem. In 1940, he joined the
Haganah, and in 1942, he enlisted in the
British Army to fight in
World War II. He saw action in Europe with the
Jewish Brigade. Following the war, Gichon became one of the
Nakam, who hunted down and killed former Nazis, and was among the Jewish Brigade veterans who organized
Aliyah Bet, or illegal immigration of Holocaust survivors to Palestine. Gichon was placed in charge of an assembly point in the
Netherlands from where Holocaust survivors were sought out and helped in their journey to Palestine. He was discharged from the British Army in 1946, and returned to Palestine, where he resumed his studies at the Hebrew University of Jerusalem. In 1947, he rejoined the Haganah and served as an intelligence officer in the
Jerusalem area during the
1947–48 Civil War in Mandatory Palestine. During the
1948 Arab-Israeli War, Gichon served in the newly created
Israel Defense Forces, and established military intelligence units in the Jerusalem area. Following the war, Gichon remained in the IDF as a career military intelligence officer, and in 1950 he was promoted to the rank of lieutenant colonel. He served in several senior positions, and was involved in the 1956
Sinai Campaign. He retired from the army in 1963. During his military service, he completed a
master's degree in 1956. ==Academic career==