States and territories disestablished in 1461

Byzantine Greek state on Black Sea coast

Chaldia (, Khaldia) was a historical region located in the mountainous interior of the eastern Black Sea, northeast Anatolia (modern Turkey) in Western Asia. Its name was derived from a people called the Chaldoi (or Chalybes) that inhabited the region in antiquity. Chaldia was used throughout the Byzantine period and was established as a formal theme, known as the Theme of Chaldia (Greek: θέμα Χαλδίας), by 840. During the Late Middle Ages, it formed the core of the Empire of Trebizond until its fall to the Ottoman Empire in 1461.