Arrange these stages of the empire’s seventh-century transformation in the order they occurred.

1. Heraclius defeats Persia and recovers the eastern provinces
2. Arab armies take Syria, Palestine and Egypt
3. Cash revenue collapses with the loss of Egyptian grain and taxes
4. Provinces are reorganised into themes under military governors
5. Greek replaces Latin as the language of administration

The bitter joke of the century is the first two steps: Heraclius won the last Roman–Persian war and lost the provinces he had just recovered within ten years. The themes and the switch to Greek are consequences, not causes, the empire redesigned itself around what it still had.