Johann Ketzko was born in approximately 1793. He served in Napoleon's army and fought against the Russians. He was captured by the Russians, and in 1812, was settled in the Volga German colony of Katharinenstadt. He is recorded there on the 1834 Census of Katharinenstadt in Household No. 341 along with a note that he had moved to the colony of Beauregard in 1826.
- 1834 Census of Katharinenstadt.
- Belousov, S.V. "Prisoners of war of Napoleon's army in the Volga region: the arrangement, content, relationships with the local population." Bulletin of the Samara State University, No. 1 (Samara, Russia: Samara State University, 2006): 48-55.