The terms anno Domini (AD) and before Christ (BC) are used when designating years in the Julian and Gregorian calendars. The term anno Domini is Medieval Latin and means "in the year of the Lord" but is often presented using "our Lord" instead of "the Lord", taken from the full original phrase "anno Domini nostri Jesu Christi", which translates to "in the year of our Lord Jesus Christ". The form "BC" is specific to English, and equivalent abbreviations are used in other languages: the Latin form, rarely used in English, is ante Christum natum (ACN) or ante Christum (AC).
Anno Domini inscription at Klagenfurt Cathedral, Austria
Statue of Charlemagne by Agostino Cornacchini (1725), at St. Peter's Basilica, Vatican City. Charlemagne promoted the usage of the anno Domini epoch throughout the Carolingian Empire.
The Julian calendar is a solar calendar of 365 days in every year with an additional leap day every fourth year. The Julian calendar is still used as a religious calendar in parts of the Eastern Orthodox Church and in parts of Oriental Orthodoxy as well as by the Amazigh people.
The Tusculum portrait of Julius Caesar
Russian icon of the Theophany (the baptism of Jesus by John the Baptist) (6 January), the highest-ranked feast which occurs on the fixed cycle of the Eastern Orthodox liturgical calendar
