Created either in the mid-7th or the early 8th century as the settlement of the former Army of Thrace, after which it was named, it was one of the larger and more important themes of the Empire throughout its existence based on its proximity to Constantinople.

[2][8][9] This origin is reflected in the mythical story narrated by Emperor Constantine VII (reigned 913–959) in his De Thematibus, whereby the region was named after some Thracians settled there in the early 6th century BC by Alyattes of Lydia.

[12][13] Other notable governors of the theme include Bardanes Tourkos, who was its stratēgos in the 790s and rebelled against Nikephoros I (r. 803–811) in 803;[12] Constantine Kontomytes, who defeated the Cretan Saracens at Mount Latros in 841 and married into the imperial family;[14] Petronas, the uncle of Michael III (r. 842–867) and the Empire's leading general, in 856–863;[15] and Symbatios the Armenian, who along with the governor of the Opsician Theme George Peganes tried to oppose the growing power of Basil the Macedonian, Michael III's protégé who eventually usurped the throne from him.

[16] The same process saw the theme gradually becoming a peaceful backwater; when the formidable general Constantine Diogenes was named its stratēgos in 1029, the appointment was seen as a demotion, intended to curb his suspected designs on the throne.

[1][18] It was reconstituted under the Nicaean Empire, and by this time consisted of the katepanikia of Smyrna and Anaia along the Aegean coast, and the chora of Pyrgion and Kaloe in the upper Kaystros valley.

[19] The Thracesian Theme was one of the last Byzantine territories in Asia Minor to fall to the various Turkish beyliks, and played an important role as a bulwark against their raids.

[1] The theme of the Thracesians comprised the ancient regions of Ionia (the late Roman province Asia), Lydia, the northern half of Caria, and part of Phrygia Pacatiana.