Thomas de Hartmann’s birthdate is generally stated as being 21 September 1885, but his birth record has been found in the baptismal records of Mikhailovsky church in Khoruzhivka, Ukraine, which shows that 21 September is the O.S. date, and the year is in fact 1884. This church record (in Russian) can be seen at: https://www.familysearch.org/ark:/61903/3:1:3Q9M-CS9Y-FSZ1-G?i=91&cat=982910, image 92
