History of Opium

"There is evidence for the existence of opium poppy in Europe as long ago as 4,200 B.C. and even earlier.a There are also references towards opium use in ancient Greece, starting around 1,500 B.C. during the Minoan culture, with various references in the 7th century B.C. (Iliad and Odyssey) and during the reign of Alexander the Great (4th century B.C.) whose troops and medical doctors apparently introduced opium to Central Asia and India.b In Asia, opium was already produced and used by the Sumerians earlier than 3000 B.C, in Mesopotania (today’s Iraq)c from where the know-how was passed on to the Assyrians, the Babylonians, the Egyptians (1,300 B.C.) and other peoples in the region.6 China got acquainted to opium via Arab merchants, with dates given in the literature ranging from around 4th7 to the 8th century A.D.8"

Source: 

United Nations Office on Drugs and Crime. A Century of International Drug Control. UNODC: Vienna, Austria, 2009.