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.
Lewis Einstein
Einstein's diplomatic career began in 1903, when he was appointed as Third Secretary of Legation at Constantinople. The next year, he married Helen Ralli, a noted English beauty a number of years older than he, whose sister was married to the younger son of Francis Stonor, 4th Baron Camoys. This marriage led to friction between Einstein and his father, who worried that Ralli would damage the younger Einstein's career; Ralli was twice a divorcee, and divorced women could not be received in some European courts.