'Circa' (often abbreviated 'c.', 'ca.', 'ca' or 'cca.' and sometimes
italicized to show it is
Latin) literally means "
about". It is widely used in
genealogy and historical writing, when the dates of events are ''approximately'' known.
For example, an encyclopedia entry for
Genghis Khan may begin with "Genghis Khan (circa 1162–August 18, 1227)".
When used in date ranges, a circa is applied before each approximate date, while dates without a circa immediately preceding them are generally assumed to be known with certainty. For instance, the 1162 in the above example is approximate, but the August 18, 1227 is known.
See also
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