Stephan Kekulé von Stradonitz
Stephan Kekulé von Stradonitz (1 May 1863 in Ghent – 5 May 1933 in Berlin), was a German lawyer, heraldist and genealogist who popularized a genealogical numbering system of ancestors.
Stephan was the son of the prominent chemist Friedrich August Kekulé von Stradonitz, descended from a Czech noble family from Bohemia, and his Belgian wife Stéphanie Drory.
In 1898 Kekulé von Stradonitz published his interpretation of Eytzinger's and Sosa's method in his Ahnentafel-Atlas. Ahnentafeln zu 32 Ahnen der Regenten Europas und ihrer Gemahlinnen, Berlin: J. A. Stargardt, 1898–1904, containing 79 charts of the sovereigns of Europe and their wives. This method became the most common method of numbering ancestors and is known as the Sosa–Stradonitz Method or Ahnentafel.