Yossi Harel, who died on Saturday at 90, was the commander of Exodus 1947, the immigrant ship that tried to make it through the British blockade to Palestine after the Second World War with 4,553 Jewish refugees on board.

Exodus (its original name was the President Warfield) was a ship purchased in November 1946 in America by Mossad Lealiya Bet, the clandestine agency charged with bringing illegal Jewish immigrants to Palestine, then under British Mandate.

Yossi Harel was appointed to command the ship while it was still in Italy undergoing refitting and conversion from a Chesapeake Bay steamer to a passenger ship. Between June 29 and July 6, 1947, 4,553 Jews from displaced persons camps in Germany were transported to Sète, a little town 85 miles west of Marseilles where, on July 11, they boarded the ship.

Under Harel’s command Exodus set sail for Palestine on July 12, 1947, and, after it had left French territorial waters, the British cruiser Ajax and several destroyers escorted it to Haifa with the aim of arresting it and preventing the immigrants from entering Palestine.

Harel planned with the skipper, Yitzhak (Ike) Aaronowitz, that close to the coast of Palestine they would “get rid” of the British escort. The plan, Harel later recalled, was “to turn off all the ship’s lights at a given moment, stop suddenly so that the unwary destroyer would pass us by, and then change our course by 90 degrees and steam away at full speed ahead — 18-19 knots — with all the lights out.” On board, Harel also prepared the stiffest possible resistance against any potential British attempt to board the ship.

On Friday, July 18, when Exodus was 22 miles off the coast of Palestine, Harel was informed by the British that his ship had entered the territorial waters of Palestine and that he had to shut down the engines and surrender. With five British destroyers closing in, Harel felt he could not implement his plan of evasion and instead ordered his captain to ignore the British warning and head straight for Haifa harbour.

When Harel failed to obey the British command, Exodus’s bow was hit and a detachment of troops attempted to board the ship. But under Harel’s leadership the British troops were driven back by a volley of canned goods, bolts, and potatoes. British commandos soon managed to take the ship’s wheel, however, by which point several holes had been made in the ship’s wooden structure. Harel — after a strenuous argument with his skipper, who was keen to continue fighting — ordered the immigrants to cease their resistance and allow the ship to be towed into Haifa. Three Jews and a British soldier died during the operation.

The next day members of the United Nations Special Committee (UNSCOP), who happened to be in Palestine on a fact-finding mission, witnessed the transfer of the refugees to three British transports, which were to return the Jews to Europe. This affair greatly affected UNSCOP in its decision to recommend an end to British Mandate in Palestine and argue for the creation of a Jewish state in part of the territory. Exodus was often described as “the ship that launched a nation.”

The incident reached a wider audience still when Leon Uris’s novel “Exodus,” which also became a film starring Paul Newman, described the affair in a lively and dramatic (though fairly inaccurate) fashion.

Yossi Harel was born Yossef Hamburger in Jerusalem in 1917, and began his military career at 20, when he joined the Special Night Squads set up in Palestine by Captain Orde Wingate to fight Arab bands.

In 1941, Palmach was established as the elite force of the Hagana, the clandestine military organization of the Jewish community in Palestine, and Harel soon joined it. He was sent by Palmach to work with Mossad Lealiya Bet in assisting Jews to enter Palestine illegally (the number of Jews allowed to enter the territory was restricted by the British after 1939).

In mid-1946 Harel was sent from Palestine on a secret mission to transfer gold to Jewish agents in Greece so they could bribe officials in European governments to speed up the transit of Jews to Palestine.

Harel chartered a 15-ton trawler with a crew of four and boarded it at sea after leaving the coastal settlement of Bat Galim in a rowboat. Because of storms the journey to Greece took three weeks, but eventually the mission was accomplished successfully and with it Harel’s reputation as a brave, reliable, and efficient soldier was established; it was later to be crucial in his selection as the commander of the Exodus operation.

During Israel’s War of Independence, Harel acted as adviser on naval reorganization to the prime minister David Ben Gurion and was sent to America to purchase vessels for a future navy. The Israeli navy was established in November 1948, and Harel was one of the candidates to lead it, but the job eventually went to a graduate of the Americal naval officers’ school in Minneapolis, Paul Shulman, with Harel becoming his deputy.

Soon after the War of Independence, Harel retired and became bodyguard to President Chaim Weizmann; he then moved to Los Angeles to study.

In February 1959, he returned to Israel to become commander of Unit 131, a division of military intelligence responsible for secret groups in enemy countries, designed to operate primarily in time of war. A year later he retired from the Israeli Defense Force to pursue a successful business career, though it served also as a cover for his continuing work for Mossad. He spent the last few years of his life collecting avant-garde Russian art.

In 2007 Harel received the Exodus prize, awarded by the Italian government to those who promote peace and humanitarianism. The prize is awarded every year at La Spezia in Italy, where Exodus was renovated.

Yossi Harel is survived by his wife, Julie, and three children.