Ibbi-Sin in the context of Ishbi-Erra

King of the Four Corners of the World (Sumerian: lugal-an-ub-da-limmu-ba, Akkadian: šarru kibrat arbaim, šar kibrāti arbaʾi, or šar kibrāt erbetti), alternatively translated as King of the Four Quarters of the World, King of the Heaven's Four Corners or King of the Four Corners of the Universe and often shortened to simply King of the Four Corners, was a title of great prestige claimed by powerful monarchs in ancient Mesopotamia. Though the term "four corners of the world" does refer to specific geographical places within and near Mesopotamia itself, these places were (at the time the title was first used) thought to represent locations near the actual edges of the world and as such, the title should be interpreted as something equivalent to "King of all the known world", a claim to universal rule over the entire world and everything within it.

The title was first used by Naram-Sin of the Akkadian Empire in the 23rd century BC and was later used by the rulers of the Neo-Sumerian Empire, after which it fell into disuse. It was revived as a title by a number of Assyrian rulers, becoming especially prominent during the Neo-Assyrian Empire. The final ruler to claim the title was the first Persian Achaemenid king, Cyrus the Great, after his conquest of Babylon in 539 BC.