Islands of large, medium, and small sizes surround the land area of Greece. Their role during the medieval period is determined by their size, productive capabilities, their position within networks, their distance from the shores, and their contribution to defense or their function as shelters during times of raids.
The pressures they face correspond to the evaluation of these parameters by aspiring conquerors. Then there is the terrain of the land area of Greece, a key factor in the political fragmentation of the Hellenic world during antiquity. Roman and Byzantine rule did not eliminate this diversity, as populations from isolated mountainous areas, which cover 3/4 of the land area of Greece, populations that presumably do not participate in the intellectual tradition and administration, emerge with different degrees of reception and adaptation to the codes emanating from the center.
This terrain does not favor the control of the total population, a control that mainly focuses on zones of defensive and fiscal interest. Because, despite the extensive and quite specialized administrative network, the state seems to primarily control the commercial centers, the productive lowland areas, and the regions accessible to its officials.
Moreover, the historical function of areas with mountainous populations, which supply the plains and the city with products, as well as a workforce characterized by particular mentalities, is generally not recorded in the sources. However, in the historical narrative, their presence and function are evident in the broader composition of the medieval Greek world, with echoes, shades, and traditions that reach up to our time.
