Hans Albert Einstein
Hans Albert Einstein was born on May 14, 1904 in Bern, Switzerland, where his father, Albert Einstein, worked as a clerk in the patent office. His father was of German-Jewish descent and his mother, Mileva Marić, Serbian-Orthodox. His younger brother, Eduard Einstein, was born in 1910 and died in 1965. The fate of his older sister, Lieserl Einstein, Albert Einstein's and Mileva Marić's first child, is unknown. Their parents divorced in 1919 after living apart for five years.
Maximilian Herzberger
Maximilian Herzberger was the son of Leopold Herzberger (born 7 Mar 1870, Krefeld — died in Rochester (NY)) and Sonja/Sofia Behrendt/Berendt/Berends (22 Mar 1876, Petersburg (Germany) — 28 Jan 1945, Florence); he had a sister Olga (24 Sep 1897, Berlin — 2 Aug 1922, Berlin). The family was Jewish.
He studied mathematics and physics at the Berlin University, where Albert Einstein was one of his professors, and later became a friend and advisor.
In 1923, Herzberger finished his Ph.D. thesis "Ueber Systeme hyperkomplexer Grössen" under Ludwig Bieberbach and Issai Schur at the philosophical faculty.
In 1925, he married Edith Kaufmann (10 Oct 1901, Stuttgart — 16 Feb 2001, Carlsbad (California) or New Orleans);
they had three children, born in Jena, viz. Ruth (born 1928), Ursula Bellugi (1931), and Hans (6 Aug 1932, spouse of Radhika Herzberger).
No later than Sep 1930, he was assistant of Hans Boegehold, the chief of calculation office at Carl Zeiss Jena.