The Land of Shinar was a general geographic term for what is today Iraq, known in ancient times as Mesopotamia (see also Bible Places). There, two of the greatest of ancient empires, Assyria and Babylon, were centered (see Ancient Empires - Assyria and Ancient Empires - Babylon). Shinar is mentioned very early in Bible History, it being the location of the famous "tower of Babel" that was constructed after the Flood.
"Even as Nimrod the mighty hunter before The Lord. And the beginning of his kingdom was Babel, and Erech, and Accad, and Calneh, in the land of Shinar"
The Land of Shinar was the site of the kingdoms founded by Nimrod:
"And Cush begat Nimrod: he began to be a mighty one in the earth. He was a mighty hunter before The Lord: wherefore it is said, Even as Nimrod the mighty hunter before The Lord. And the beginning of his kingdom was Babel, and Erech, and Accad, and Calneh, in the land of Shinar." (Genesis 10:8-10 KJV)
After The Flood, humans soon got back to their arrogant, defiant-of-God ways:
"And the whole earth was of one language, and of one speech. And it came to pass, as they journeyed from the east, that they found a plain in the land of Shinar; and they dwelt there. And they said one to another, Go to, let us make brick, and burn them thoroughly. And they had brick for stone, and slime [that is, Bitumen] had they for mortar."
"And they said, Go to, let us build us a city and a tower, whose top may reach unto heaven; and let us make us a name, lest we be scattered abroad upon the face of the whole earth."
"And The Lord came down to see the city and the tower, which the children of men builded. And The Lord said, Behold, the people is one, and they have all one language; and this they begin to do: and now nothing will be restrained from them, which they have imagined to do. Go to, let us go down, and there confound their language, that they may not understand one another's speech."
"So The Lord scattered them abroad from thence upon the face of all the earth: and they left off to build the city. Therefore is the name of it called Babel; because The Lord did there confound the language of all the earth: and from thence did The Lord scatter them abroad upon the face of all the earth." (Genesis 11:1-9 KJV)
One of the earliest recorded Middle East wars was fought among a number of kings, including the king of Shinar:
"And it came to pass in the days of Amraphel king of Shinar, Arioch king of Ellasar, Chedorlaomer king of Elam, and Tidal king of nations; That these made war with Bera king of Sodom, and with Birsha king of Gomorrah, Shinab king of Admah, and Shemeber king of Zeboiim, and the king of Bela, which is Zoar. All these were joined together in the vale of Siddim, which is the salt sea. Twelve years they served Chedorlaomer, and in the thirteenth year they rebelled."
"And in the fourteenth year came Chedorlaomer, and the kings that were with him, and smote the Rephaims in Ashteroth Karnaim, and the Zuzims in Ham, and the Emims in Shaveh Kiriathaim, And the Horites in their mount Seir, unto Elparan, which is by the wilderness. And they returned, and came to Enmishpat, which is Kadesh, and smote all the country of the Amalekites, and also the Amorites, that dwelt in Hazezontamar."
"And there went out the king of Sodom, and the king of Gomorrah, and the king of Admah, and the king of Zeboiim, and the king of Bela, the same is Zoar; and they joined battle with them in the vale of Siddim; With Chedorlaomer the king of Elam, and with Tidal king of nations, and Amraphel king of Shinar, and Arioch king of Ellasar; four kings with five. And the vale of Siddim was full of slimepits [that is, Bitumen]; and the kings of Sodom and Gomorrah fled, and fell there; and they that remained fled to the mountain." (Genesis 14:1-10 KJV)
Fact Finder: Is Shinar (also translated as "Babylonia") mentioned in a Prophecy about a future gathering of Israel and Judah?
See also The Gathering of Israel and Judah and Spiritual and Physical Gatherings