Johannes Rotgau was born in approximately 1792 in the Pfalz. 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 Mariental. He is recorded on the 1834 Census of Mariental, on the 1850 Census of Mariental in Household No. 160, and on the 1857 Census of Mariental in Household No. 175.
- 1834 Census of Mariental.
- 1850 Census of Mariental.
- 1857 Census of Mariental.
- 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.