August Schaak came from Holland to Prussia, and on to Russia.
August married Renatha Maschke. She was German and Swedish and was born about 1835 and died about 1912 in Russia.
August Schaak and Renatha Mashke Schaak had a daughter: Renatha Schaak Glaesman (aka Renatha Dzak) , born December 11, 1865.
The name Schaak is spelled many ways. Dzak, Shook, Schak Kujat, Dischak…
August Schaak was the maternal grandfather of Johann Glaesman.