The tectonic history of the eastern Mediterranean as well as the present tectonic style are affected by the collision and accretion of oceanic plateaus at subduction zones. Small but distinct oceanic plateaus exist today in the eastern Mediterranean away from the plate boundary. Many other oceanic plateaus crowd the plate boundary, particularly in the Hellenic arc area. Their presence results in the unusual complexity of this subduction zone, as is evidenced by the seismicity and bathymetry patterns. The present two arcs system in this region, the Hellenic and Cyprean arcs, is probably the consequence of the collision of a large continental plateau with an older arc. This plateau has been thrusted over the continental mass of Anatolia and pieces of it are to be found in the region between the two arcs. Active subduction in the Hellenic arc takes place in the outer trenches, particularly in the Ionian and Strabo trenches. Subduction of Mediterranean lithosphere in the Pliny and Ptolemy trenches is limited to their western parts. Inner segments of these trenches served as the main subduction trenches before the subduction zones migrated outward following the collision of oceanic plateaus.