Choma was located in the upper valley of the Maeander River in Phrygia. After the Battle of Manzikert, it became an isolated Byzantine outpost surrounded by Turkish-controlled territory. Its troops, the so-called Chomatenoi (Χωματηνοί), figure frequently in the campaigns of Nikephoros III Botaneiates (r. 1078–1081) and Alexios I Komnenos (r. 1081–1118). Due to its strategic location on one of the roads leading to the interior of Anatolia, it became a major base of operations for the Komnenian emperors' campaigns to push back the Turks. In the 12th century, it formed its own district, that of "Choma and Cappadocia", under a toparches.
Choma remained under constant Turkish threat throughout the 12th century. Emperor Isaac II Angelos (r. 1185–1195, 1203–1204) refortified it in 1193, and renamed it Angelokastron (Ἀγγελόκαστρον) after his dynasty. Choma finally fell to the Turks a short time after the dissolution of the Byzantine Empire by the Fourth Crusade in 1204.
The fortress of Soublaion, located nearby, which was rebuilt by Emperor Manuel I Komnenos (r. 1143–1180) in 1175 but abandoned after the Battle of Myriokephalon, used to be identified by earlier scholars with Choma.