It was instituted by Constantine, although there are some indications that such a tax existed during the reign of Caligula (see Suetonius, Lives of the Twelve Caesars).
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Libanius, Zosimus and Evagrius list examples of the hardships caused by this tax, probably because it was collected in one lump sum every four years.
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According to the early Byzantine writer Zosimus, Emperor Constantine I first initiated this tax, perhaps as early as 325, .
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The ecclesiastical historian Evagrius says that Constantine found the tax already established in the Eastern Empire, and considered abolishing it.