Rachamim was born in April 1929, in Jerusalem, to  David and  Chaviva. He studied at “Tachkemoni School”, and joined  “Hano’ar-Ha’oved” youth movement. He received agricultural training at Nahalal. From there he reached Palmach recruits. On “Black Saturday”, June 29,1946, he was sent by the British to  Rafiach Camp  with  his group.“A joyous child ”, the other prisoners said, “ playful even at  Detention camp”. “Black Saturday” ignited the “Hebrew Revolt Movement’s” disintegration. Rage resulting from  British persecution of  Jewish institutions, influenced the Movement’s High Command, allowing  Etzel to place a bomb in  King David Hotel’s administrative wing. However after the explosion brought  harsh reactions, Hagannah disassociated itself from the operation. Mutual allegations commenced and an internal quarrel broke out again. Rachamim, a sensitive boy with  national consciousness, was deeply disturbed by this turn of events. When he discovered the accusations were simply a tool that Hagannah/Palmach employed to refrain from fighting – he left them and joined  Lehi, chosing his nom-de-guerre, “Yoav”.

Rachamim was active in Lehi nearly two years. When the British regime began crumbling, winter 5708, he took part in operations  against Arabs and British. When the Jewish inhabitants of Romema were officially advised to evacuate (impossible to defend them), he convinced his parents to remain and taught his mother weapons use. Rachamim participated in Lehi’s actions to drive attacking Arabs from his neighbourhood, and from Lifta and Sheikh- Bader, actions that led to the fortification of the city’s Western entrance by an Israeli force.The British Mandate was nearly over but British vehiclesl roamed the city. A  Dingo vehicle – large two engine jeep with steering wheels front and back-  caught Lehi men’s attention. A small group including Rachamim, made an improvised barrier at the city’s entrance, near the road to Giv’at-Shaul, to capture a Dingo. Unfortunately, British patrol vehicles appeared and in the ensuing gun battle, April 27,1948,  Rachamim lost his life. Buried in Sanhedria, his body was later transferred to Mt. Herzl, September 6,1951.  Lehi’s Yoav Base in Sheikh-Bader was named after him.