A further diplomatic ploy was the use of surrogates. The Byzantines hated the expense of war and could hardly afford the cost in human life. Often they would get others to fight for them. If the Bulgars were troublesome, the Russians were called in. If the Russians were troublesome the Patzinaks (a central Asian tribe) were summoned. The Cumans and Uzes acted as checks on the Patzinaks and so on. The Byzantines almost always had an ally to the geographic rear of a potential enemy.

The Byzantine emperor maintained a ‘stable’ of pretenders to almost every foreign throne in the known world. For instance, if the Turkish sultan seemed poised to attack, the Byzantine emperor could release a pretender, perhaps a younger brother of the Sultan. With Byzantine gold in his pockets and some armed supporters, the pretender could be counted on to wreak havoc in Turkish territory, spoiling the Sultan’s attack.

In 1282, faced once again by the threat posed by Charles of Anjou, Michael VIII helped instigate the War of the Sicilian Vespers, in which native Sicilians rose up against Angevin rule. The rebellion ended Charles’ dream of ruling in Constantinople. Michael VIII himself wrote: ‘should I dare to claim that I was God’s instrument to bring freedom to the Sicilians, then I should only be stating the truth’.

The word ‘byzantine’ has come to mean ‘devious or characterised by intrigue’. This is due to some of the plots of questionable morality (but indisputable utility) that Byzantine emperors concocted. The Byzantines were of the opinion that anything done in the name of the Sacred Empire could not be judged treachery. Though they were diligent in adhering to the letter of their international agreements, they often violated the spirit of them. Strategic advantage was sought with fervour in every situation.