Barbarian incursions and civil wars brought on an economic crisis in the 3rd century. Subsequent to reforms introduced by Diocletian and Constantine the Great Macedonia experienced a period of economic recovery in the 5th century. Its fertile plains, cultivated by freeholders and villeins paying rent to large landowners, produced mainly cereal crops and wines.
The inland road network comprised two main routes: the Via Egnatia and a highway which traversed the Axios valley and reached from the areas around the Danube to Thessalonike. These routes facilitated the holding of trade fairs (e.g. the Demetria) and served the movement of agricultural products and livestock, and of the products of craft industries based in important Balkan urban centers (Thessalonike, Stoboi, Herakleia Lynkestis, Amphipolis, Neapolis).
Sea trade with the western Mediterranean and the Near East, whence the merchants settled in Thessalonike had originated, was conducted out of the ports of Neapolis (present-day Kavala) and especially Thessalonike. Exploitation of the publicly owned salt-pans, forests, metal ore mines and quarries (Thasos) played an important part in the economy of the region.
Miniature from an 11th century Gospel
Despite the progressive concentration of wealth in the hands of landowners the standard of living of the urban middle class (doctors, architects, teachers, merchants, cooks, and professionals organised into guilds) was high. Guilds under state control worked marble, manufactured metal articles of everyday use (some in 'Chalkeon', the coppersmiths' quarter in Thessalonike), weaponry, bricks, tiles and mosaics, and traded tanned hides, and textiles (mostly purple-dyed).