The Altalena Affair was a violent confrontation that took place in June 1948 by the newly created Israel Defense Forces against the Irgun (also known as IZL), one of the Jewish paramilitary groups that were in the process of merging to form the IDF. The confrontation involved a cargo ship, Altalena, captained by Monroe Fein and led by senior IZL commander Eliyahu Lankin, which had been loaded with weapons and fighters by the independent Irgun, but arrived during the murky period of the Irgun's absorption into the IDF.