Elsa Einstein (18 January 1876 – 20 December 1936) was the second wife and cousin of Albert Einstein. Their mothers were sisters, thus making them maternal first cousins. Further, their fathers were first cousins, making the couple paternal second cousins too. Elsa had the surname of Einstein at birth, lost it when she took the name of her first husband Max Löwenthal, She and her daughters reverted to her maiden name, Einstein, after her 1908 divorce. Early life Elsa, the daughter of Rudolf Einstein and Fanny Einstein (née Koch), was born in Hechingen on 18 January 1876. She had two sisters: Paula (c. 1878–c. 1955) and Hermine (1872–1942). Rudolf was a textile manufacturer in Hechingen. During the regular visits with the family in Munich, she often played with her cousin Albert. In her Swabian dialect, she called him "Albertle". The two parted ways in 1894, when Albert left Germany to follow his family to Milan. Married life In 1896, Elsa married textile trader Max Löwenthal (1864–1914), from Berlin, with whom she had three children: daughters Ilse (1897–1934) and Margot (1899–1986), and a son who was born in 1903, but died shortly after birth. They lived together in Hechingen. In 1902, Max Löwenthal took a job in Berlin. His family stayed in Hechingen. She divorced Max on 11 May 1908, and moved with her two daughters to an apartment above her parents on Haberlandstrasse 5, in Berlin. She and her daughters reverted to her maiden name, Einstein, after her 1908 divorce. She began a relationship with her cousin Albert Einstein in April 1912, while Albert was still married to his first wife, the physicist and mathematician Mileva Marić. Einstein separated from Mileva in July 1914. He sent her with the two sons back to Zürich. Their dedicated divorce was final on 10 February 1919. Elsa married him three and a half months later, on 2 June 1919. With stepdaughters Ilse and Margot, the Einsteins formed a close-knit family. Although Albert and Elsa did not have any children of their own, Albert raised Ilse and Margot as his own. They lived in the Berlin area, also having since 1929 a summer house in Caputh in nearby Potsdam. Ilse also served as Einstein's secretary for a brief period. Elsa spent most of her marriage with Albert acting as his gatekeeper, protecting him from unwelcome visitors and charlatans. She also was the driving force