In antiquity aregion between Thrace and Epiros comprising the watersheds of the Haliakmon and Vardar rivers.
CentralMacedonia is a large plain dominated by the city of Thessalonike, with Serres and Philippi in the east and Kastoria, Berroia, Ohrid, and Prespa in the west.
In the 4th century Macedonia was a province in the diocese of Moesia; by the time of the 'Notitia Dignitatum' it was divided into Macedonia Salutaris and Macedonia II. This administrative structure was retained in the 6th century: Hierokles calls Thessalonike the capital of Macedonia I and Stoboi that of Macedonia II. Constantine VII Porphyrogennetos anachronistically described Macedonia I as an 'eparchia' (under a 'consularis') containing 32 cities and Macedonia II (under a 'hegemon') as having eight cities.
In the late 6th-7th century much of Macedonia was occupied bySlavs, resulting in cultural difurcation: Slavs controlled the countryside and upland regions while Byzantines retained possession of most of the towns.
Byzantine reconsolidation began in the 8th century.
A new administrative unit, the theme of Macedonia, was created in 797-801, according to P.Koledarov (IzvInstBulgIst 21  219-43). Theophanes (Theoph.475.22) mentions a 'monostrategos' in Thrace and Macedonia active in 801/2. At the same time, a 9th century seal of Leo, 'spatharios' and 'tourmarches' of Macedonia (Zacos, Seals 1, no.2147), shows that Macedonia was first a 'tourma' of Thrace.
In 813, however, the 'patrikios' John Aplakes served as 'strategos' of Macedonia. Several seals of various 'strategoi' of Macedonia belong to the 9th century. The office of the 'strategos' of Macedonia is mentioned in the earlier 'taktika' but not in the 'Taktikon of the Escurial' of 971-75 (Oikonomides, Listes 355); the theme of Macedonia was probably replaced by that of Larissa -at ant rate, a 'strategos' of "Larisa and Makaidonia" in 1006/7 founded a church in Tao (K.Juzbasjan in Ellinisticeskij Bliznij Vostok, Vizantija I Iran [Moscow 1967] 115).
In Byzantine terminology of the 10th-12th centuries the name 'Macedonia' was applied to Thrace: thus, Niketas Choniates (Nik.Chon. 6.22-24) calls Adrianople one of the richest and strongest 'poleis' of Macedonia, and Basil I, born in Thrace, was founder of the "Macedonian" dynasty. A 13th century historian (Akrop. 23.3-16) lists Philippopolis, Herakleia, Rhaidestos, and many other Thracian 'poleis' as located in Macedonia.
On the other hand, a 14th century historian (Greg. 1:524.18, 3.99.15, 100.7) distinguishes Thrace from Macedonia, and Kantakouzenos (Kantak. 3:104.20) sees Macedonia as a region that included Thessalonike (N.P.Andriotes, BalkSt 1  147).
After 1204 all of Macedonia fell under the control of Boniface of Montferrat, king of Thessalonike. The area was invaded by Kalojan and conquered by Theodore Komnenos Doukas of Epiros in 1222, then by John III Vatatzes ca.1242.
The Chalkidike became a base for the Catalan Grand Company in 1307-08 and much of Macedonia fell to Stephan Uros IV Dusan ca.1345. The Ottomans conquered Macedonia in the late 14th century, although some cities held out into the early 15th century.
The metropolitans of Macedonia were the bishops of Thessalonike and Philippi; they were under the authority of the papacy until 732/3, afterwards under Constantinople.
Culturally, Macedonia formed a single unit, although the settlement of the Slavs created some division and the successive Bulgarian and Serbian states contested political control with Buzantium.
Thessalonike dominated the south and Ohrid, from the 9th century, the north. Macedonia was the center from which Byzantine culture reached the Slavs of the Balkans. Both Thessalonike and Ohrid developed cultural forms of their own, and one may speak of distinctly Macedonian styles of architecture and painting, although these were always strongly influenced by Constantinople and individual styles developed in many rural parts of Macedonia.
Oxford Dictionary of Byzantium (1991), vol.2, pp.1261,1262