Arnold Joseph Toynbee. Constantine Porphyrogenitus and his world. Oxford University Press, 15 March 1973. ISBN 978-0-19-215253-4. A further settlement of 208,000 Slavs was planted in Bithynia (part, by then, of thema Opsikion), on the River ... The earliest piece of evidence for a deportation of Slavs from the Balkan Peninsula to Asia Minor may be a seal inscribed ... This seal is dated 'the eighth indiction', and this might be either the year 649/50 or the year 694/5. Since it is on record that 5,000 Slavs deserted from the East Romans to the Arabs as early as 664/5,1 Charanis dates the seal 650, and this dates the first deportation of Slavs from the Balkan Peninsula to Asia Minor in the reign of Constans II ...
