Victory stele of Naram-Sin of Akkad. Bronze Age In the 26th century BC, Eannatum of Lagash created what was perhaps the first empire in history, though this was short-lived. Later, Lugal-Zage-Si , the priest-king of Umma , overthrew the primacy of the Lagash dynasty in the area, then conquered Uruk , making it his capital, and claimed an empire extending from the Persian Gulf to the Mediterranean. From the 29th century BC, Akkadian Semitic names began to appear on king lists and administrative documents of various city states.
It remains unknown as to the origin of Akkad, where it was precisely situated and how it rose to prominence. Its people spoke Akkadian , an East Semitic language. The influences between Sumerian and Akkadian are evident in all areas, including lexical borrowing on a massive scale—and syntactic, morphological, and phonological convergence. This mutual influence has prompted scholars to refer to Sumerian and Akkadian of the 3rd millennium BC as a Sprachbund. Bill of sale of a male slave and a building in Shuruppak , Sumerian tablet, circa BC.
Between the 29th and 24th centuries BC, a number of kingdoms and city states within Iraq began to have Akkadian speaking dynasties; including Assyria , Ekallatum , Isin and Larsa. However, the Sumerians remained generally dominant until the rise of the Akkadian Empire — BC , based in the city of Akkad in central Iraq.
Sargon of Akkad , originally a Rabshakeh to a Sumerian king, founded the empire, he conquered all of the city states of southern and central Iraq, and subjugated the kings of Assyria, thus uniting the Sumerians and Akkadians in one state.
He then set about expanding his empire, conquering Gutium , Elam and had victories that did not result into a full conquest against the Amorites and Eblaites of Ancient Syria.
After the collapse of the Akkadian Empire in the late 22nd century BC, the Gutians occupied the south for a few decades, while Assyria reasserted its independence in the north. This was followed by a Sumerian renaissance in the form of the Neo-Sumerian Empire. The Sumerians under king Shulgi conquered almost all of Iraq except the northern reaches of Assyria, and asserted themselves over the Gutians , Elamites and Amorites , destroying the first and holding off the others. An Elamite invasion in BC brought the Sumerian revival to an end.
By the mid 21st century BC, the Akkadian speaking kingdom of Assyria had risen to dominance in northern Iraq. Assyria expanded territorially into the north eastern Levant, central Iraq, and eastern Anatolia, forming the Old Assyrian Empire circa — BC under kings such as Puzur-Ashur I , Sargon I , Ilushuma and Erishum I , the latter of whom produced the most detailed set of law yet written[ citation needed ]. The south broke up into a number of Akkadian speaking states, Isin , Larsa and Eshnunna being the major ones.
During the 20th century BC, the Canaanite speaking Amorites began to migrate into southern Mesopotamia. Eventually, they began to set up small petty kingdoms in the south, as well as usurping the thrones of extant city states such as Isin , Larsa and Eshnunna. Hammurabi , depicted as receiving his royal insignia from Shamash. Relief on the upper part of the stele of Hammurabi's code of laws.
One of these small Amorite kingdoms founded in BC contained the then small administrative town of Babylon within its borders. It remained insignificant for over a century, overshadowed by older and more powerful states, such as Assyria, Elam, Isin, Ehnunna and Larsa. In BC, an Amorite ruler named Hammurabi came to power in this state, and immediately set about building Babylon from a minor town into a major city, declaring himself its king. Hammurabi conquered the whole of southern and central Iraq, as well as Elam to the east and Mari to the west, then engaged in a protracted war with the Assyrian king Ishme-Dagan for domination of the region, creating the short-lived Babylonian Empire.
He eventually prevailed over the successor of Ishme-Dagan and subjected Assyria and its Anatolian colonies. By the middle of the eighteenth century BC, the Sumerians had lost their cultural identity and ceased to exist as a distinct people. However, his empire was short-lived, and rapidly collapsed after his death, with both Assyria and southern Iraq, in the form of the Sealand Dynasty , falling back into native Akkadian hands.
The foreign Amorites clung on to power in a once more weak and small Babylonia until it was sacked by the Indo-European speaking Hittite Empire based in Anatolia in BC.
After this, another foreign people, the Language Isolate speaking Kassites , originating in the Zagros Mountains of Ancient Iran , seized control of Babylonia, where they were to rule for almost years, by far the longest dynasty ever to rule in Babylon. Iraq was from this point divided into three polities: Assyria in the north, Kassite Babylonia in the south central region, and the Sealand Dynasty in the far south.
Beginning with the campaigns of Ashur-uballit I , Assyria destroyed the rival Hurrian - Mitanni Empire, annexed huge swathes of the Hittite Empire for itself, annexed northern Babylonia from the Kassites, forced the Egyptian Empire from the region, and defeated the Elamites , Phrygians , Canaanites , Phoenicians , Cilicians , Gutians , Dilmunites and Arameans.
The Kassites were driven from power by Assyria and Elam, allowing native south Mesopotamian kings to rule Babylonia for the first time, although often subject to Assyrian or Elamite rulers. However, these East Semitic Akkadian kings, were unable to prevent new waves of West Semitic migrants entering southern Iraq, and during the 11th century BC Arameans and Suteans entered Babylonia from The Levant , and these were followed in the late 10th to early 9th century BC by the migrant Chaldeans who were closely related to the earlier Arameans.
It was during this period that an Akkadian influenced form of Eastern Aramaic was adopted by the Assyrians as the lingua franca of their vast empire, and Mesopotamian Aramaic began to supplant Akkadian as the spoken language of the general populace of both Assyria and Babylonia. The descendant dialects of this tongue survive amongst the Mandaeans of southern Iraq and Assyrians of northern Iraq to this day.
Relief showing a lion hunt , from the north palace of Nineveh , — BC. In the late 7th century BC, the Assyrian Empire tore itself apart with a series of brutal civil wars, weakening itself to such a degree that a coalition of its former subjects; the Babylonians , Chaldeans , Medes , Persians , Parthians , Scythians and Cimmerians , were able to attack Assyria, finally bringing its empire down by BC. It failed to attain the size, power or longevity of its predecessor; however, it came to dominate The Levant , Canaan , Arabia , Israel and Judah , and to defeat Egypt.
Initially, Babylon was ruled by yet another foreign dynasty, that of the Chaldeans , who had migrated to the region in the late 10th or early 9th century BC. Its greatest king, Nebuchadnezzar II , rivalled another non native ruler, the ethnically unrelated Amorite king Hammurabi , as the greatest king of Babylon.
However, by BC, the Chaldeans had been deposed from power by the Assyrian born Nabonidus and his son and regent Belshazzar.
The Achaemenids made Babylon their main capital. The Chaldeans and Chaldea disappeared at around this time, though both Assyria and Babylonia endured and thrived under Achaemenid rule see Achaemenid Assyria. Little changed under the Persians, having spent three centuries under Assyrian rule, their kings saw themselves as successors to Ashurbanipal, and they retained Assyrian Imperial Aramaic as the language of empire, together with the Assyrian imperial infrastructure, and an Assyrian style of art and architecture.
In the late 4th century BC, Alexander the Great conquered the region, putting it under Hellenistic Seleucid rule for over two centuries. From Syria , the Romans invaded western parts of the region several times , briefly founding Assyria Provincia in Assyria. Christianity began to take hold in Iraq particularly in Assyria between the 1st and 3rd centuries, and Assyria became a centre of Syriac Christianity , the Church of the East and Syriac literature. A number of independent states evolved in the north during the Parthian era, such as Adiabene , Assur , Osroene and Hatra.
During the s and 's AD, the Sassanids gradually conquered the independent states, culminating with Assur in AD. The region was thus a province of the Sassanid Empire for over four centuries, and became the frontier and battle ground between the Sassanid Empire and Byzantine Empire , with both empires weakening each other, paving the way for the Arab - Muslim conquest of Persia in the mid-7th century.
Middle Ages The Abbasid Caliphate at its greatest extent, c. Under the Rashidun Caliphate , the prophet Muhammad 's cousin and son-in-law, Ali , moved his capital to Kufa when he became the fourth caliph.
The Umayyad Caliphate ruled the province of Iraq from Damascus in the 7th century. The Abbasid Caliphate built the city of Baghdad in the 8th century as its capital, and the city became the leading metropolis of the Arab and Muslim world for five centuries. Baghdad was the largest multicultural city of the Middle Ages , peaking at a population of more than a million,  and was the centre of learning during the Islamic Golden Age.
The Mongols destroyed the city and burned its library during the siege of Baghdad in the 13th century. This angered Hulagu, and, consistent with Mongol strategy of discouraging resistance, he besieged Baghdad , sacked the city and massacred many of the inhabitants. The Mongols destroyed the Abbasid Caliphate and Baghdad's House of Wisdom , which contained countless precious and historical documents. The city has never regained its previous pre-eminence as a major centre of culture and influence.
Some historians believe that the Mongol invasion destroyed much of the irrigation infrastructure that had sustained Mesopotamia for millennia. Other historians point to soil salination as the culprit in the decline in agriculture. After the capture of Baghdad, 20, of its citizens were massacred.
During the late 14th and early 15th centuries, the Black Sheep Turkmen ruled the area now known as Iraq. From the earliest 16th century, in , as with all territories of the former White Sheep Turkmen, Iraq fell into the hands of the Iranian Safavids. Owing to the century long Turco-Iranian rivalry between the Safavids and the neighbouring Ottoman Turks , Iraq would be contested between the two for more than a hundred years during the frequent Ottoman-Persian Wars. With the Treaty of Zuhab in , most of the territory of present-day Iraq eventually came under the control of Ottoman Empire as the eyalet of Baghdad as a result of wars with the neighbouring rival, Safavid Iran.
Throughout most of the period of Ottoman rule — , the territory of present-day Iraq was a battle zone between the rival regional empires and tribal alliances. By the 17th century, the frequent conflicts with the Safavids had sapped the strength of the Ottoman Empire and had weakened its control over its provinces.
The nomadic population swelled with the influx of bedouins from Najd , in the Arabian Peninsula. Bedouin raids on settled areas became impossible to curb. During the years —, Iraq was ruled by a Mamluk dynasty of Georgian  origin who succeeded in obtaining autonomy from the Ottoman Porte , suppressed tribal revolts, curbed the power of the Janissaries, restored order and introduced a programme of modernisation of economy and military.
In , the Ottomans managed to overthrow the Mamluk regime and imposed their direct control over Iraq. The population of Iraq, estimated at 30 million in AD, was only 5 million at the start of the 20th century.
In the Mesopotamian campaign against the Central Powers, British forces invaded the country and initially suffered a major defeat at the hands of the Turkish army during the Siege of Kut — However, subsequent to this the British began to gain the upper hand, and were further aided by the support of local Arabs and Assyrians.
An armistice was signed in The British lost 92, soldiers in the Mesopotamian campaign. Ottoman losses are unknown but the British captured a total of 45, prisoners of war. By the end of , the British had deployed , men in the area, of which , were combat troops.