“The Indiction was a cycle of fifteen years, which are severally styled Indiction 1, Indiction 2, &c., up to Indiction 15, when the series begins afresh. The introduction of this system is attributed to Constantine the Great. From the circumstance of the commencement of the indiction being reckoned variously from different days, four kinds of indictions have been recognized, viz.:—
“i. The Indiction of Constantinople, calculated from the 1st of September, a.d. 312.
“ii. The Imperial or Caesarian Indiction (commonly used in England and France), beginning on the 24th of September, a.d. 312.
“iii. The Roman or Pontifical Indiction (commonly used in dating papal bulls from the ninth to the fourteenth century), beginning on the 1st of January (or the 25th of December, when that day was reckoned as the first day of the year), a.d. 313.
“iv. The Indiction used in the register of the parliament of Paris, beginning in October.
“The Greeks made use of the Indiction of Constantinople[290].
“To find the indiction of a year of the Christian era, add 3 to the year (because a.d. 1= Indiction 4), and divide the sum by 15: if nothing remains, the indiction will be 15; if there is a remainder, it will be the number of the indiction. But it must not be forgotten that the Indiction of Constantinople begins on the first of September, and consequently that the last four months of a year of the Christian era belong to the next indiction year.
“The year of the Creation of the World was calculated, according to the era of Constantinople, to be b.c. 5508. The first day of the year was the 1st of September.
“To reduce the Mundane era of Constantinople to the Christian era, deduct 5508 from the former for the months of January to August; and 5509 for September to December.
“A chronological table, showing the corresponding years of the Mundane era, the Christian era, and the Indiction, from a.d. 800 to a.d. 1599, will be found in Gardthausen's ‘Griechische Palaeographie,’ pp. 450-459.”