Kilwa Kisiwani: Coins from Songo Mnara

The town of Songo Mnara was found on a small island near the major port city of Kilwa Kisiwani, in what is now southern Tanzania. Kilwa Kisiwani itself was the seat of several major Swahili dynasties, starting in the 11th century with the migration of foreign traders to the area- whether these traders were local, or members of the Persian elite remains a disputed claim. In any case, by the time that Songo Mnara was established in the late 13th-early 14th century, culture on the Swahili coast was an extremely cosmopolitan mixture from extensive exposure to Indian Ocean trade routes.

This cosmopolitan culture is well reflected in the coins presented here as well. Featured in Arabic script are the name of the current Kilwa Sultan is placed in a rhyming pair with a Holy Name of Allah [2]. Additional inspection reveals that coins excavated from this location come in three different metals: gold, silver, and copper, suggesting a tiered system of value. Furthermore, analysis of the physical dimensions of these coins reveal an impressive level of standardization: over four centuries the coins maintain an average diameter of 2.0-2.2 cm (approximately the diameter of a nickel), with standard deviation < 1.30 mm [2]. Notably, in the collection at Songo Mnara it is possible to find altered coins, exemplified by those pictured above: there are coins that look to have been intentionally broken into fractions (halves, fourths), in addition to those sporting grooves, or pierced by a hole.