Thracesian Theme The Thracesian Theme ( , " Thrakēsion thema " ) , more properly known as the Theme of the Thracesians ( , " thema Thrakēsiōn " , often simply , " Thrakēsioi " ) , was a Byzantine theme ( a military - civilian province ) in western Asia Minor ( modern Turkey ) . Created either in the mid - 7th or the early 8th century , it was one of the larger and more important themes of the Empire throughout its existence . History . As with the other themes , the exact date of foundation is unclear . The Thracesians are first securely attested in 711 , when a " " tourmarchēs " of the Thracesians " named Christopher was dispatched against Cherson by Emperor Justinian II , while and a governing " stratēgos " is only attested as late as 741 . It is hence traditionally assumed that Thracesians were initially a " tourma " ( division ) of the Anatolic Theme , and that they were raised to a full theme some time after 695 , probably in the early years of the 8th century , but the phrasing of the sources does not make clear whether that was the case already in 711 . Some modern scholars , like Ralph - Johannes Lilie and John Haldon , however , have argued that the Thracesian army is to be identified with the " Thracianus exercitus " ( " Thracian army " ) mentioned in a decree of 687 , and that consequently the Thracesian theme was one of the original themes established in Asia Minor . The name of the theme derives from the fact that the themes were formed in the mid - 7th century as military encampment areas for the remnants of the old field armies of the East Roman army , following the Muslim conquests ; in the case of the Thracesians , the field army of the " magister militum per Thracias " . This is further supported by the fact that units that are known to have been part of the latter in the 4th / 5th centuries , the " vexillatio palatina " of the " Equites Theodosiaci Iuniores " and the " auxilium palatinum " of the " Victores " , are attested again as the thematic " tourmai " of the " Theodosiakoi " and " Viktores " in the 10th century . This provides the Thracesian theme with the distinction of fielding some of the oldest known units of the Byzantine army . This origin is reflected in the mythical story narrated by the Byzantine 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 . The first known " stratēgos " of the Thracesians , a certain Sisinnios , supported Constantine V ( r . 740 – 775 ) against the usurper Artabasdos ( r . 741 – 742 ) , but was himself later blinded by the emperor when he suspected him of conspiracy . Constantine took care to appoint a series of governors loyal to him and his policies ; the most prominent among them being the ardent iconoclast Michael Lachanodrakon . Lachanodrakon launched a brutal persecution of iconophiles , especially the monks , so that by 772 , in the words of historian Warren Treadgold , he seems to have succeeded in " eradicating monasticism within his theme " . 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 ; Constantine Kontomytes , who defeated the Cretan Saracens at Mount Latros in 841 and married into the imperial family ; Petronas , the uncle of Michael III ( r . 842 – 867 ) and the Empire ' s leading general , in 856 – 863 ; and Symbatios , 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 . In the 10th century , as the threat of Arab raids subsided , the soldiers of the Thracesians appear to have been used more and more in overseas expeditions , such as the expeditions sent against the Emirate of Crete in 911 , 949 and 960 . The same process saw the theme gradually becoming a peaceful backwater ; by 1029 , the appointment of one of the Empire ' s most capable generals , Constantine Diogenes , who was suspected of harbouring designs on the throne , to the position of its " stratēgos " was seen as a demotion , and as a measure to curb his power . The theme was briefly conquered by the Seljuk Turks in the 1070s , but most of its territory was recovered by John Doukas with the help of the First Crusade ( 1096 – 1099 ) . John II Komnenos ( r . 1118 – 1143 ) re - established it , albeit in a reduced size , under a " doux " with seat at Philadelphia . The southern portion of the old theme became part of the new theme of Mylasa and Melanoudion . The theme was one of the last Byzantine territories in Asia Minor to fall to the various Turkish beyliks , and important as a bulwark against their raids . By the early 14th century , however , it had been restricted to the area around Smyrna , until that city also fell to the Beylik of Aydın in 1330 . Geography and administration . 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 . The theme was bordered on the west by the Aegean Sea , with its coastline stretching from Ephesus to Adramyttion , the Opsician Theme in the north , probably along the valley of the river Caicus ) , the Anatolic Theme in the east ( somewhere east of Chonae and Laodicea on the Lycus ) , and the Cibyrrhaeot Theme in the south . The theme contained some 20 cities , although most of them were much reduced from their late antique status . Smyrna and Ephesus ( also known as " Theologos " at the time ) were probably the largest among them . The Persian geographer Ibn Khordadbeh ( wrote ca . 847 ) mentions Ephesus as the capital , but this is not certain ; it may instead have been at Chonae . The theme ' s governing " stratēgos " ranked in the first tier of thematic governors and received an annual salary of 40 pounds of gold . The Arab geographer Qudama ibn Ja ' far ( wrote ca . 930 ) gives the troops under his command as 6 , 000 , while Ibn al - Faqih ( wrote ca . 903 ) puts them as high as 10 , 000 . In 949 , its senior - most officers were , in order of rank , the " tourmarchēs " of the " Theodosiakoi " , the " tourmarchēs " of the " Viktores " , the " tourmarchēs " of the seacoast ( " tēs paraliou " ) , and a " meriarchēs " . The coast was also under the parallel authority of the " stratēgos " of the naval theme of Samos , who drew crews and ships from there .