Armenia has always had an ambiguous place between the major powers, be they the East Roman empire and Sasanian Iran, the Byzantine empire and the caliphate, or the Ottoman empire and the Safavids. Armenian loyalties have not been consistent, either in support of a coherent internal policy or with regard to external diplomacy. The very definition of Armenia highlights the problem. Does the term refer to a geographical entity – and if so, what are its borders? Or does it refer to a people with common bonds – and if so, are those bonds linguistic, religious, cultural or political?1 Despite the conversion of King Tiridates IV (c. 283–330) to Christianity, probably in 314,2 and the establishment of an organised church, the continuing strength of Iranian traditions and the cultural and kinship ties of the Armenian nobility to Iran made Armenia an uncertain ally for the Romans. Yet since the Armenian monarchy was a branch of the Arsacid dynasty which had been overthrown by the Sasanians in 224, relations between Armenia and Iran were already strained. Tiridates’ conversion compounded an already difficult situation, for the shahs naturally became suspicious of the future loyalty of Armenians to their Iranian heritage.3 In the fifth century, attempts by the shahs to impose Zoroastrianism led to armed conflict – while to the west, the Armenians found their relationship with fellow Christians increasingly marred by their involvement in the struggles over orthodoxy. The division of Armenia c. 387 into two monarchies and two spheres of influence – a large Iranian sector east of a line running from Sper toMartyropolis (see map 8), and a much smaller Roman sector west of that line up to the Euphrates – did not solve ‘the Armenian question’.4 Both powers were to find Armenia a difficult neighbour.