Jovan Uroš Nemanjić or John Ouresis Doukas Palaiologos or Joasaph of Meteora, was the ruler of Thessaly from c. 1370 to c. 1373, retiring as a monk for the next half century thereafter. He died in 1422 or 1423.

The Meteora is a rock formation in the regional unit of Trikala, in Thessaly, in northwestern Greece, hosting one of the largest and most precipitously built complexes of Eastern Orthodox monasteries, second in importance only to Mount Athos. The six monasteries are built on immense natural pillars and hill-like rounded boulders that dominate the local area. Between the 13th and 14th centuries, the twenty-four monasteries were established atop the rocks. Meteora is located near the town of Kalabaka at the northwestern edge of the Plain of Thessaly near the Pineios river and Pindus Mountains.