Natan was born in Grodno, which was then part of the Russian Empire, populated mostly by Jews. His father Shmuel, was a master builder who played the clarinet as a hobby. When he was a year old, World War I broke out and his father was drafted into the Russian Army.

His father never returned. His mother, Hannah, was left with no means of support and three children, so she moved back to her parents’ home in Lipsko, where only fourteen Jewish families lived. The place was a battlefield between empires, and the power games and terrors of war made quite an impression on the boy. In his youth, his thirst for education and knowledge was clear. At 4½, he started studying Hebrew. His teacher was one of the Lithuanian intellectuals, teaching him not only Talmud, but Hebrew, Bible and mathematics. At age seven, the family learned of his father’s death. In Lipsko, he completed five grades in public school. In order to continue his studies, he travelled to Grodno, while his mother and sister stayed in his grandparents’ home. Grodno had a grand Jewish tradition, and many learned intellects resided there, where many educational institutions and ideological movements flourished—Zionist, religious, and communist.

Natan was accepted into the Tarbut Hebrew gymnasium. There he received his basic education in Hebrew and Jewish culture. He also acquired a love for writing and publishing.

Two events influenced him at that time. The first was the atmosphere of the gymnasium, which was like a piece of Eretz Israel. The Zionist movements were very popular in the school, and most of the gymnasium students joined. The second influence was Polish Romantic literature and its heroic narratives. The poetry of Juliusz Słowacki and Adam Bernard Mickiewicz and the novels of Henryk Sienkiewicz inspired young Natan. In 1932, he finished his studies and assumed responsibility over all Beitar branches throughout Poland.

In 1933, he left his birthplace and went to Warsaw. Here he was asked to serve in the Beitar leadership, eventually becoming an officer. In 1935, he passed, with flying colors, the entrance exams to Warsaw Polytechnic’s structural engineering program. However, aliyah was always on his mind.  He wanted to work as a structural engineer in Eretz Israel, without being dependent on party politics. He was active in Beitar and Zohar, and he became acquainted with the Revisionist leaders: Zeev Jabotinsky, Uri Zvi Greenberg, Abba Ahimeir, Menachem Begin and others, working with them.

After the murder of Haim Arlosoroff in 1933 and Jabotinsky’s resignation from the World Zionist Organization, the Revisionist Movement became deflated and dispirited. There was a widening gap between its stated goals and the actions to realize them. Most of all, the Beitar youth began to despair of their chances of achieving their dream of aliyah. Natan was also discouraged by the ideological dampening. In light of the 1936 Arab riots, he underwent a crisis of confidence in the movement, leading him to realize that Beitar would never lead its youth in a war for the future of Eretz Israel.

In the summer of 1937, there was a dramatic turning point in his life. His friend, Abraham Stavsky, who had been convicted for Arlosoroff’s murder (overturned by the Supreme Court), introduced him to Avraham “Yair” Stern, who was then establishing IZL’s “nationalist cells.” Yair convinced Natan to join, explaining that in Eretz Israel, the Hebrew national liberation movement was forming, to fight the British occupier and free the land from their grasp. Tens of thousands of Jewish youths had to be prepared, armed and trained, then brought to Eretz Israel, Yair explained. Natan wrote about this in Shnot BeTerem (The Ere Years), describing his feeling after meeting Yair: he was no longer the same man. From here on in, he would dedicate his life to the Hebrew liberation movement in Eretz Israel.

Natan threw himself into his work. He walked every path in Poland, meeting youth, bringing them the gospel according to Yair and his plans. In every town, he left behind another cell. Many of these youngsters would eventually make aliyah and participate in the underground war. He also assisted Stavsky in the illegal aliyah program called “Af al Pi.” Later, with Yair’s encouragement, he set up with his friend, Shmuel Merlin, the IZL newspaper in Poland in Yiddish, called Di Tat, and became its editor. Di Tat became a daily, detailing the events happening in Eretz Israel and the activities of IZL. Nevertheless, it constantly warned of the impending destruction in Europe, taking issue with both Zionist and non-Zionist Jewish newspapers, which tried to reassure the public. In fact, the final edition of August 25th, 1939, less than a week before the war, stated: “This night is a fateful night for world peace.” When this newspaper closed, Natan was the editor of Moment for a short time. With the outbreak of war, Natan married Frieda Morin, and the two decided to leave Warsaw and head east, towards Eretz Israel. Together with Aliza and Menachem Begin, they took the train to Lviv, then continued by wagon and foot, fleeing the German blitzkrieg, all the way to Vilnius in Lithuania, where hundreds of refugees were concentrated, members of Beitar and IZL. After a year in Lithuania, they received an exit visa from the Soviet authorities and they left by way of Kovno, Moscow, and Odessa, to Istanbul, Turkey. From there, by way of Syria and Lebanon, he and Frieda reached Eretz Israel on January 8th, 1941.

Without hesitation, Natan joined Yair, and he became his trusted advisor for the next few months. Natan became the editor the underground newspaper BaMahteret. He chose the nom de guerre “Gera,” while Frieda became “Efrat.” One day, Yair proposed to Natan a very important political mission: to travel to the Balkans and encourage the governments there to send their Jews to the Land of Israel. Yair was worried about the Jews remaining there.

Natan set out for Syria as an engineer working for a contractor in Jerusalem who built airfields for the Royal Air Force near the Turkish border. From there he had intended to continue to the Balkans. But one day, when he returned home from his work, he was arrested by the British CID. He was transferred first to Aleppo and then, via Beirut, to Haifa and then Jaffa. After many interrogations, he was sent to the Acre prison and then to the Mizra camp. How did the British find out about him?

The night he left for Syria, Frieda lent their flat to the underground. There was much activity in the flat, with many arriving to stay there. One day in February of 1942, the police arrived at the flat, apparently due to an informer. Frieda was arrested. They found a note with Gera’s address in Syria inside of Frieda’s purse. That note got him sent to Mizra.

The murders of his friends Avraham Amper and Selig Jacques before his imprisonment and the murder of Yair a few days after his imprisonment impacted Gera deeply, but he believed that the war for liberation was not over and the foreign occupier would soon be banished from the homeland.

Gera never accepted imprisonment. From the moment of his arrival, he planned his escape. After Yitzhak “Michael” Shamir escape from Mizra in 1942, Gera became the senior prisoner among the Lehi men. While Michael rebuilt the underground in Eretz Israel form the outside, Gera did his work from the inside, using his literary acumen. His essay, “Tearing down the Prison Walls,” published in the revived BaMahteret, did a great deal to buoy the spirits of the underground fighters. He explained that detention was a dangerous weapon in the enemy’s hands, serving to break the freedom fighters’ spirit and take away their freedom, taking them off the battlefield. So the choice was clear: the underground or the prisons. The prisons had to be destroyed; no fighter could allow himself to be taken captive. He must use his weapons to defend his freedom and his life. Either the underground would destroy the prisons, or the prisons would destroy the underground. There was no third option.

In Latrun, he planned and executed a daring escape with nineteen of his comrades through a 75-meter tunnel on November 1st, 1943. Throughout this time, Gera was in charge of the Lehi prisoners. Once he got out, the central committee of Lehi was founded, and his bailiwick was political and foreign affairs. After the arrest of Dr. Israel Eldad, he was charged with editing the Lehi newspaper, HaHazit. Gera, sought by the CID, took another pseudonym, Asher Wilensky. He had to constantly keep moving from one residence to another, every few days. In 1944, he joined discussions with IZL and Haganah leaders about collaboration, but nothing came of those talks.

As a central committee member, he was a full partner for everything concerning the underground and its policies, until the State of Israel was established. While Michael and Eldad were imprisoned, he had the responsibility of other duties for the underground. These included the assassinations of Lord Moyne and High Commissioner MacMichael (attempted), as well as attacks on other strategic and military targets in order to achieve Lehi’s goal: destroying the foreign occupier absolutely. Early in 1945, the saison de chasse conducted by the Haganah against IZL and Lehi began, and Gera met with Eliyahu Golomb. His threats and demands convinced the Haganah to call off its actions against Lehi. Early in September 1945, after the saison ended, Gera met Israel Galili, Moshe Sneh and Menachem Begin. They agreed to set up a body for collaboration against the British, and for the next nine months, the Jewish Resistance Movement was active.

With the publication of the new Lehi magazine, HaMaas, Gera became the editor-in-chief and published many essays. He managed to avoid arrest during the great curfew of Tel Aviv in the summer of 1946, but Michael was caught and exiled to Africa. Gera then was in charge of the organizational direction of the underground. At this time, he instituted a new foreign-relations policy for Lehi, the “neutralization of the Middle East,” based on the removal of all foreign actors and imperialists from the Middle East, for the benefit of all the peoples of the region. He sent dozens of representatives abroad in order to set up branches for the movement and to forge connections with governments, institutions and people. He softened the emphasis of centralization, which had inhibited growth.

At the same time, he had some differences with Eldad, concerning the “neutralization of the Middle East” and the pro-Soviet orientation, in response to the support expressed by the Soviet Union for Lehi’s plans. Eldad supported an independent foreign policy. After the UN Resolution, they publish together a declaration opposing the Partition of Palestine: “The Freedom Fighters of Israel will continue to fight for the unity of the land with the proper tactics for each time and place.” As for the Arabs of Eretz Israel, Gera believed “the national interests of the Hebrew people and the essential interests of the inhabitants of the land, without any distinction of national origin, religion or race, dovetail with each other.” He thought that the struggle against the Arabs would not become a race war, but would be understood as promoting self-defense and restoring civil order. The central committee of Lehi, under Gera’s leadership, published pamphlets in Arabic calling for peace, brotherhood and a joint war against the imperialists victimizing them all and setting them at loggerheads.

In late 1947, HaMivrak, a new Lehi daily, came out. Under the headline, “Our Vision of a Just State,” Gera called for a political approach based on socialist Zionism, expanding on his views expressed in HaMaas. In this essay, he called for equal opportunity for every child according to his skills and abilities, for a fair distribution of the burdens and the joys of life, for universal education and for a state of justice and equality.

Approaching the Declaration of Independence, the central committee of Lehi decided to demobilize and enlist in the IDF, while continuing to fight for Jerusalem’s liberation and annexation to the State of Israel. On September 17th, 1948, the central committee of Lehi decided to assassinate Count Folke Bernadotte, the UN representative, for the crime of trying to force an agreement which would require Israel to relinquish much of Eretz Israel and to hand over Jerusalem to the Arabs, annexing it to Jordan. Gera was arrested and brought before a military tribunal. He was sentenced to imprisonment for membership in an illegal organization, but he was freed under the general pardon. Once the battles died down, the Fighters’ Party was established with Lehi veterans, with two ideological camps: one was headed by Gera and Michael and was a revolutionary socialist party, while the second was headed by Eldad, who wanted to establish an educational movement for the philosophy of Israeli freedom. Gera was chosen to be the representative of this party and served in the 1st Knesset. Two years later, the Knesset was dissolved, and the party fell apart, so he pursued personal interests. From 1954 to 1965, he was in charge of the largest private farm in Eretz Israel.

In 1956, he created a new movement called Semitic Action, together with some leftist intellectuals. Its Hebrew Manifesto was published in 1958-1959, containing revolutionary ideas of the place of the Hebrew people among the broader Semitic milieu: a secular, democratic state, a free socialist economy, universal education and a binding constitution. Between 1960 and 1967, he published a bi-weekly by the name of Etgar (Challenge), which served as an ideological forum for left-wing intellectuals seeking a peaceful solution to the Israeli-Arab conflict. After the Six-Day War, he published essays in the daily papers about a peace plan based on two states for two peoples. He maintained connections with Arab leaders and peace movements throughout the Western world and the Eastern Bloc, participating in many international conferences in order to advance peace initiatives.

In 1969, his party, Nes, failed to get seats. After the Yom Kippur War, he brought messages of peace from Egyptian emissaries to the government, but these were rejected.

In 1974, he published his book, Freedom Fighters of Israel – Personalities, Ideas, and Adventures, in which he explained Lehi’s battle and its policies, describing the events and the personalities of the movement. Shnot BeTerem, his autobiography, describing his experiences in Poland and his journey to Eretz Israel during World War II, was discovered posthumously and published in 1990.

Into the 70’s, he continued to write essays about peace, economics and society.

Natan and Frieda (she too was a Lehi member) had two children, Dorit and Elisha, and two grandchildren.

Natan Yallin-Mor, Gera, one of the leaders of Lehi, was a newspaperman, a publisher and a humanist, a man who dedicated his entire lfie to the establishment of a Jewish state in the Land of Israel. He died on February 18th, 1980. His wife Frieda passed away on August 9th, 1994. Both were buried in the Lehi plot in Holon Cemetery.