The ship was built by the Fairfield Shipbuilding and Engineering Company of Glasgow in 1892 for the Northern Lighthouse Board and served as a tender, named Pole Star, based at Stromness.
[3] Both men were members of Mossad LeAliyah Bet, a branch of Haganah that organised illegal Jewish emigration from Europe to the British Mandate of Palestine.
[3] They planned to take the Darien II to a port in Yugoslavia to rescue 822 Jews from Poland, Germany and Austria, who had attempted to leave Europe in the ship Uranus via the Danube, but had been stranded at Kladovo on the Romanian/Yugoslav border.
[2] The ship then became involved in a struggle between two branches of Haganah, one dedicated to bringing Jewish refugees from Europe to Palestine in defiance of British restrictions, and the other actively co-operating with the British Special Operations Executive (SOE) to provide Jewish agents to carry out acts of sabotage and intelligence gathering in enemy territory.
On 17 February 1941 Darien II left Constanța with 460 refugees on board, arriving at Varna, Bulgaria, the next day.
When the Bulgarian authorities arrested the ship's captain, Olaf Bergenson, a former Norwegian naval officer, was appointed to command.
[3] Among the refugees aboard Darien II were Abba Berdichev, who joined SOE and was parachuted back into Europe only to be caught and executed by the Germans, and Shulamit, later wife of prime minister Yitzhak Shamir.