As of 2001, Greek companies owned around 3,000 merchant vessels—more than any other country and about 18 percent of the world’s fleet. The Greeks have been maritime traders for millennia, but the modern prominence of their shipping industry dates from the end of World War II. In the late 1940s, the United States government began to sell off surplus war ships under the Ship Sales Act. Savvy Greek maritime businessmen like Aristotle Onassis and (the elder) Stavros Niarchos purchased large tanker vessels and smaller ships at incredible bargains, sometimes through illegal means.