Dionysius Exiguus (Latin for "Dionysius the Humble") (c.470 – c.544 AD) was a 6th-century monk born in Scythia Minor (probably modern Dobruja, which is in Romania and Bulgaria). He was a member of a community of Scythian monks concentrated in Tomis, the major city of Scythia Minor. Dionysius is best known as the inventor of the Anno Domini (AD) era, which is used to number the years of both the Gregorian calendar and the (Christianized) Julian calendar. Some churches adopted his computus (calculation) for the dates of Easter.