You may be thinking, ‘Gee, dating by consuls sure was fun. How else did Romans write the years in dates?’ Let me tell you, if consular dating is your bag, you’ll love indictions. I was reminded of the ancient Roman indiction cycle recently, since my current research has brought me up against Pope Gregory VII (pope, 1073-85), who uses this system in his letters, thus:
Data Rome VIIII. Kalendas Maii, Indictione XI.
Given at Rome, 8 days before the Kalends of May (24 April), in the eleventh indiction.
One may quickly jump to the conclusion that this is some medieval popery. After all, doesn’t Gregory the Great (pope, 590-604), who comes after The End of Ancient Christianity use indictions as well? Aha, but what sort of man was this first Pope Gregory? Gregory the Great was a Roman aristocrat of senatorial descent who owned a villa on the Caelian Hill, had spent time in the imperial court of Constantinople, and who acted as though Gaul was part of the Empire, not an independent, Frankish kingdom.
Not the sort of guy to go around using new-fangled dating systems.
However, the consulate was gone by Gregory’s day (the last consul was Basilius in 541). But the consulate was not the only way to write a year. Nonetheless, people did not universally and immediately start writing things Anno Domini according to their favourite paschal tables and systems of computus. They did keep using some of the older systems, and the indiction gains greater prominence at this time, at least from what my own, informal glance at the evidence shows.
Two questions, then: What on earth is an indiction? Who used them?
The indiction can be very unhelpfully explained as a fifteen-year cycle for late Roman taxation purposes. It was instituted by the Emperor Constantine (possibly originally developed by Diocletian, r. 284-305), and definitely in use in Egypt (whence come so many useful papyri for this sort of thing) by 313. What this means is that the emperors declared what the average valuation for taxation would be for the next fifteen years. The fifteen years themselves form the indiction. The very first indiction, proclaimed in 313, was backdated to 1 September 312. Every 1 September, every 15 years, a new indiction started, with the start of a new fiscal cycle for the imperial administration.
When used in dates as the Gregory VII quotation above, the word indiction actually refers to one of the fifteen years of the cycle. Thus, if people had been using the indiction in this way in 312 (which I’m pretty sure they weren’t), then ‘first indiction’ would refer to 1 September 312 – 31 August 313. Then the second indiction would begin, and so on for fifteen years. Then the cycle starts again with the new fiscal term.
One of the things this reminds us of — and it’s something I like to point out — is that Constantine, like Diocletian before him, was a reformer and shaper, and he would have been a big deal even without converting to Christianity. Indeed, perhaps his ability to think outside the conventional Roman box is part of why he threw his lot in with the Christian god.
One more small but important note is that, due to an error, in the medieval West, indictions began on 24 September. This must make chronology fun for people who look at Latin-Byzantine relations in the Middle Ages!
Anyway, that, in short, is what an indiction is. I’m probably imprecise in one or more ways; hopefully Richard will correct me in the comments.
People who use indictions to write dates:
A few Latins: Popes. Popes also used consular formulae in letters whereas such dates don’t survive for other letters. So the papal chancery is a big deal, whatever you think about institutional religion. Bede. No surprise, given that he wrote a text call On the Reckoning of Time. Cassiodorus in the Variae; I’ve not checked his historiography.
A few Greeks: Evagrius Scholasticus does sporadically, but not as his main means of dating. Theophanes Confessor.
In Syriac, at least Pseudo-Zachariah Rhetor, it seems.
Lots and lots of other people do, but I really don’t have time to hunt them all down.