Josephine Sarah Marcus, often known as Sadie, was one of four children born to German Jewish immigrant parents in Brooklyn, New York. Her father was a prosperous baker. When she was seven years old, the family moved to San Francisco, California. Josephine attended music and dance classes. At age 18, she and a friend ran way from home with a theater company, working as dancers, and traveled to the Arizona Territory. There Josephine met Johnny Behan, a deputy sheriff and rather shady character. Josephine returned home, but Behan followed and asked her to marry him. In 1880, she joined Behan in Tombstone, Arizona, but after several years, when they had not married, she left him. She began a romance with Wyatt Earp. She took Earp's surname, althought there's no formal record of their marriage, and lived with him in Tombstone and other western towns for 45 years, at times with Josephine's parents. In the 1920s, with financial aid from her sister Henrietta, the couple tried mining and oil ventures in southern California, promoting a movie about Wyatt Earp’s exploits as a lawman, and writing his life story. After Earp died in 1929, a biography by journalist Stuart Lake called Wyatt Earp, Frontier Marshal (1931) commercialized Earp and fueled further print and film depictions. Josephine produced her own version, I Married Wyatt Earp (1967), written with Earp's cousins Mabel Earp Cason and Vinola Earp Ackerman, and edited by amateur historian Glenn Boyer. Even in her own book, the facts about Josephine's life were somewhat obscured as she refused to disclose details of many events. Debates about the authenticity of the book and even the cover photograph continue among scholars and historians.