Thomas Martin Einstein
Albert Einstein had three children, Lieserl Maric (1902–1903?), Hans Albert Einstein (1904–1973), and Eduard "Tete" Einstein (1910–1965), but only Hans Albert is known to have married and had children. Hans Albert's only biological child to survive to adulthood was Bernard Caesar Einstein (1930–2008), who was a physicist and the father of Thomas Martin Einstein.
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.