Palaeolimnological evidence for an east-west climate see-saw in the Mediterranean since AD 900

► High-resolution lake climate records from Spain and Turkey show opposite trends during the last 1100 years. ► In this bipolar climate see-saw the MCA was overall dry (wet) and the LIA wet (dry) in the western (eastern) Mediterranean. ► Western Mediterranean dryness during the MCA is consistent with a persistent positive NAO state. ► The eastern Mediterranean pattern, on the other hand, cannot be explained by recent NAO teleconnections alone.