Category:Date of birth unknown

This category (and within its own specific purpose, the analogous Category:Date of death unknown) is intended for placement in biographical entries about deceased individuals, primarily from antiquity (although, in some cases, reaching into the 19th century), whose year of birth is indicated, but the month and day are lost to history and never likely to be known. "Date of birth unknown" may also be applicable to a variety of individuals from the less-remote past who gained a degree of notability at some later point in their lives, but were born in times and under circumstances which precluded the recording and/or preservation of historical data.

Except for details which should be elucidated within the pertinent biographical article, such as above-mentioned birth in a remote region where no records were/are kept, this category is not meant to include individuals in Category:Possibly living people, as well as historically recent individuals who are no longer alive, but whose date of birth is presumed to have been recorded and could be researched. All such individuals should be included in Category:Date of birth missing.

When the birth date is absent for subjects of biographical articles in Category:Living people, please refer to instructions in Category:Date of birth missing (living people).