The Arabic name العراق al-ʿIrāq has been in use since before the 6th century. There are several suggested origins for the name. One dates to the Sumerian city of Uruk (Biblical Hebrew Erech) and is thus ultimately of Sumerian origin, as Uruk was the Akkadian name for the Sumerian city of Unug, containing the Sumerian word for "city", URU. According to Professor Wilhelm Eilers, "The name al-‘Irāq, for all its Arabic appearance, is derived from Middle Persian erāq for lowlands".
Mesopotamia has always been called "the land of Iraq" in Arabic, meaning "the fertile" or "deep-rooted land". During the medieval period, there was a region called ʿIrāq ʿArabī ("Arabian Iraq") for lower Mesopotamia and ʿIrāq ʿajamī ("Persian Iraq" or "Foreign Iraq"), for the region now situated in Central and Western Iran. The term historically included the plain south of the Hamrin Mountains and did not include the northernmost and westernmost parts of the modern territory of Iraq.
As an Arabic word, عراق means hem, shore, bank, or edge, so that the name by folk etymology came to be interpreted as "the escarpment", viz. at the south and east of the Jazira Plateau, which forms the northern and western edge of the "al-Iraq arabi" area.
The Arabic pronunciation is . In English, it is either (the only pronunciation listed in the Oxford English Dictionary and the first one in Merriam-Webster's Online Dictionary) or (listed first by MQD), the American Heritage Dictionary, and the Random House Dictionary. /aɪˈræk/ is frequently heard in US media.
Iraq has the common epithet, the "Cradle of Civilization", as it was home to the earliest known civilization on Earth, the Sumerian civilization, which arose in the fertile Tigris-Euphrates river valley of southern Iraq in the Chalcolithic (Ubaid period). It was here in the late 4th millennium BC, that the world's first writing system and recorded history itself were born. The Sumerian civilization flourished for over 3,000 years and was succeeded by the rise of the Akkadian Empire in the 24th century BC. Over two centuries of Akkadian dominance was followed by a Sumerian Renaissance in the 21st century BC. An Elamite invasion in 2004 BC brought the Third Dynasty of Ur to an end. By the 18th century BC a new civilization, Babylonia, had risen to dominance in central and southern Iraq while a contemporaneous state, Assyria, had formed in northern Iraq.
In the 6th century BC, Cyrus the Great of neighbouring Persia defeated the Neo-Babylonian Empire at the Battle of Opis and Iraq was subsumed into the Achaemenid Empire for nearly four centuries. In the late 4th century BC, Alexander the Great conquered the region, putting it under Hellenistic Seleucid rule for nearly two centuries. The Parthians conquered the region during the reign of Mithridates I of Parthia (r. 171–138 BC). From Syria, the Romans invaded the region several times. The Sassanid Persians under Ardashir I destroyed the Parthian Empire and conquered the region in 224 AD. The region was thus a province of the Persian Empire for four centuries, until the Islamic conquest of Mesopotamia in the 7th century.