when did we start using ce and bce
Common Era The expression has been traced back to 1615, when it first appeared in a book by Johannes Kepler as the Latin usage vulgaris aerae,[5][6] and to 1635 in English as "Vulgar Era".[b] The term "Common Era" can be found in English as early as 1708,[7] and became more widely used in the mid-19th century by Jewish academics. In the later 20th century, the use of CE and BCE was popularized in academic and scientific publications, and more generally by authors and publishers wishing to emphasize secularism or sensitivity to non-Christians, by not explicitly referencing Jesus as "Christ" and Dominus ("Lord") through use of the abbreviation[c] "AD".[9][10]
anno Domini On the continent of Europe, Anno Domini was introduced as the era of choice of the Carolingian Renaissance by the English cleric and scholar Alcuin in the late eighth century. Its endorsement by Emperor Charlemagne and his successors popularizing the use of the epoch and spreading it throughout the Carolingian Empire ultimately lies at the core of the system's prevalence. According to the Catholic Encyclopedia, popes continued to date documents according to regnal years for some time, but usage of AD gradually became more common in Roman Catholic countries from the 11th to the 14th centuries.[27] In 1422, Portugal became the last Western European country to switch to the system begun by Dionysius.[28] Eastern Orthodox countries only began to adopt AD instead of the Byzantine calendar in 1700 when Russia did so, with others adopting it in the 19th and 20th centuries.