Dr. phil. Leo Graetz was born September 26, 1856, in Breslau. His parents were Heinrich Graetz, university professor and historian in Breslau, and Prof. Dr. Marie Graetz, née Monasch. His father died during a visit to him in Munich on September 7, 1891, and his mother died on May 31, 1900.
Leo Graetz studied mathematics and physics at the universities of Berlin (under Helmholtz and Kirchhoff) and Breslau (where he was awarded his doctorate under O. E. Meyer). In 1882/83 he completed his habilitation under Jolly with a thesis on the performance of gases under heat at the LMU Munich. In 1894 he was appointed associate professor. He was a full university professor of physics from 1907 until his retirement. His area of expertise was electricity and its application. In 1925 he was awarded the title of „Privy Counsellor“. As a member of Munich society, he had himself photographed in the Elvira studio and was painted by Franz von Stuck, a famous Munich painter.
On January 1, 1883, he married Emilie (Emmy) Heller, born November 21, 1862 in Nuremberg. They had two children, Paul, born in Munich September 19, 1895, and a daughter, Leonie (called Tana), born in Munich October 13,1884. Emilies parents were Heinrich Heller, a hop merchant at Nuremberg, and his wife Betty, née Rothchild.
Their son Paul, a businessman, moved to Leipzig in 1926, where he died November 9, 1933. Before 1912 their daughter Leonie married Ritter Ernst von Seuffert, born 1879, who was professor for medicine and Medizinalrat in the Bavarian administration.
Leonie survived the Holocaust, worked as a film critic and died April 7, 1955 in Munich. Her husband Ernst died in 1952 in Munich. They had a daughter, Thea Bach, née von Seuffert (1912-2002), who worked as an authority on the German language and an author. Herr husband was Rudolf Bach, born 1905, who died 1967. Their grave can be found at the Waldfriedhof in Munich.
Leo Graetz lived with his family in Friedrichstrasse 26 in Munich from January 1, 1904 until September 28, 1933, for almost 30 years. September 8, 1933, they were forced to move to Leopoldstrasse 4. From September 1, 1936, onward Emilie and Leo lived at Martiusstrasse 8 in the Pension Wolbach. On March 11, 1937, his wife Emilie died there. On January 12, 1938, he moved in with his daughter and son in law at Güllstraße 8. A few days before the imminent deportation to Kaunas, he died in Munich on November 12, 1941, at the age of 85. The Graetz family grave (Emmy Graetz, née Heller; Prof. Dr. Leo Graetz and Paul Graetz) is in the New Israelite Cemetery in Munich, Section 12, Row 5, Square 14.
In 1961, a street in the Munich district of Obersendling was named Leo-Graetz-Strasse in his memory.