Sîn-mÃÂgir (, <sup>D</sup>suen-ma-gir, inscribed <sup>d</sup>EN.ZU-ma-gir, âÂÂSîn upholds,âÂÂ; died 1814 BC) was the 14th king of Isin and reigned for around 11 years.
His reign falls over the last six years of Warad-Sin and the first five of Rim-Sin I, the sons of Kudur-Mabuk and successive kings of Larsa, and wholly within the reign of the Babylonian monarch Apil-Sin. There are currently six extant royal inscriptions, including brick palace inscriptions, seals for his devoted servants, such as Iddin-damu, his âÂÂchief builder,â and Imgur-Sîn, his administrator, and a cone which records the construction of a storehouse for the goddess Aktuppëtum of Kiritab in his honor commissioned by Nupá¹Âuptum, the lukur priestess or concubine, âÂÂhis beloved traveling escort, mother of his first-born.âÂÂ
An inscription marks the construction of a defensive wall, called Dà «r-Sîn-mÃÂgir, âÂÂSîn-mÃÂgir makes the foundation of his land firm,â at Dunnum, a city northeast of Nippur. Control of Nippur itself however may have shifted to Larsa, under the rule of Warad-Sin and his father, Kudur-Mabuk, the power behind the throne, as his sixth year-name celebrates that he âÂÂhad (14 copper statues brought into Nippur and) 3 thrones adorned with gold brought into the temples of Nanna, Ningal, and Utu.â Larsa was to retain Nippur until year nine of Rëm-Sîn when it was lost to Damiq-ilishu. One of the cones bearing this inscription was found in the ruins of the temple of Ninurta, the é-ḫur-sag-tÃÂ-la, in Babylon, and is thought likely to have been an ancient museum piece. The city of Dunnum, the celebration of whose original foundation may have been the purpose of the Dynasty of Dunnum myth, was taken by Rim-Sin the year before he conquered Isin and so it is conjectured that the cone was taken from Larsa as booty by Ḫammu-rapë.
Two legal tablets offered for private sale, recording sales of a storehouse and palm grove, give a year-name elsewhere unattested, âÂÂyear Sîn-mÃÂgir the king dug the Ninkarrak canal.â Another year-name marks "(Sîn-mÃÂgir) built on the bank of the Iturungal canal (the old wadi) a great fortification (called) Sîn-mÃÂgir-madana-dagal-dagal (Sîn-mÃÂgir broadens his country)." A province in the south and a town in eastern Babylonia near Tuplias are both called Bët-Sîn-mÃÂgir and some historians have speculated one or other were named in his honor.