There were three different varieties of indiction, each starting on a different day of the year.
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In some areas it was collected by indiction year, every month.
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The indiction was first used to date documents unrelated to tax collection in the mid-fourth century.
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And Albuin, king of the Langobards, moved out of Pannonia in the month of April after Easter in the first indiction.
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An indiction is any of the years in a 15-year cycle used to date medieval documents throughout Europe, both East and West.
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But usage changed, and it gradually became common to talk of the 1st indiction, the 2nd indiction, and so on.
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If the remainder is zero, then the indiction is 15.
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Dating according to indiction remained standard.
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Consular dating had already been abolished in 537, when Justinian introduced dating by the emperor's regnal year and the indiction.
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More examples
A 15-year cycle used as a chronological unit in ancient Rome and adopted in some medieval kingdoms
An indiction is any of the years in a 15-year cycle used to date medieval documents throughout Europe, both East and West. Each year of a cycle was numbered: first indiction, second indiction, etc. However, the cycles were not numbered, thus other information is needed to identify the specific year.
(Indicting) In the common law legal system, an indictment is a formal accusation that a person has committed a crime. ...
In dating terms, a repeating cycle of 15 years beginning on 1st September 312, introduced by the Emperor Constantine for taxation purposes but utilised as a dating system during the medieval era
A 15-year period having its roots in the rhythm of the assessment of taxes in the Roman empire. A five-year cycle introduced by emperor Diocletian later gave way to a 15-year period. Alongside with the number of a year only the number of that year within the current cycle was given. ...
A Latin word indicating the first day of the liturgical calendar year. In the Roman Empire the fiscal year did not coincide with the astronomical calendar. ...