Dietrich's first stage appearances were as a chorus girl in vaudeville-style revues in the 1920s. She was bisexual, and enjoyed the thriving gay scene of the time and drag balls of 1920s Berlin. She married her only husband, Rudolf Sieber, in 1923 and gave birth to her only child, Maria Elisabeth Sieber, in 1924. After some smaller parts on stage musicals and in silent films, her breakout as a star came when she was cast as Lola Lola, a magnetic cabaret singer who brought down a respectable professor, in Josef von Sternberg's The Blue Angel (1930).
The film saw international success and Dietrich moved to Hollywood under a 6-contract deal with Paramount. Her first American film was Morocco. She knew very little English and learned her lines phonetically, but earned the only Oscar nomination of her career. In Morocco she wore a tuxedo and white tie, and kissed a woman. Dietrich was known for cross-dressing and her image had (oddly, considering the times) unquestioned appeal to men and women alike. She once said, "I dress for myself. Not for the image, not for the public, not for the fashion, not for men."
Five more highly successful films were made with Paramount (also under von Sternberg's direction): Dishonored, Shanghai Express, Blonde Venus, The Scarlet Empress, and The Devil is a Woman. After the contract was up, under a different director Dietrich starred in a 1937 film that bombed, resulting in her and many other major stars being labeled as "box office poison." But she revived her stardom and went on to make many more films.
With the ascendancy of the Nazi part in Germany, which Dietrich vehemently opposed, she became an American citizen in 1939. When the United States entered World War II she became the first celebrity to raise war bonds. She toured the U.S. for a year and a half, and it is said she sold more war bonds than any other star. During 1944 and 1945 she made USO tours of Europe, even performing for troops on the front lines, even inside Germany. She sang songs, performed on her musical saw (a skill picked up during her early cabaret years), and entertained the troops with a "mind reading act" that was rife with sexual innuendo and had church groups complaining. She recorded songs for OSS use, recording at least one in German, and actually became a favorite of soldiers on both sides of the war. She also toured the military hospitals to pay personal visits to bring cheer to wounded soldiers.
Dietrich was awarded the Medal of Freedom by the United States in 1947, which she said was her proudest achievement, and the Légion d'honneur by France as well. She had been raised as a Protestant but lost her faith during her wartime experiences, once saying, "If God exists, he needs to review his plan."
From the early 1950s until the mid-1970s, Dietrich worked almost exclusively as a highly-paid cabaret artist, performing live in large theaters in major cities worldwide, working with Burt Bacharach as her arranger and recording albums with him as well.
As for her rich private life through all these decades, as summarized in Wikipedia (be careful, this may make you dizzy):
Throughout her career Dietrich had an unending string of affairs, some short-lived, some lasting decades; they often overlapped and were almost all known to her husband, to whom she was in the habit of passing the love letters of her men, sometimes with biting comments. During the filming of Destry Rides Again, Dietrich started a love affair with co-star Jimmy Stewart, which ended after filming. In 1938, Dietrich met and began a relationship with the writer Erich Maria Remarque, and in 1941, the French actor and military hero Jean Gabin. Their relationship ended in the mid-1940s. She also had an affair with the Cuban-American writer Mercedes de Acosta, who was Greta Garbo's lover. Her last great passion, when she was in her 50s, appears to have been for the actor Yul Brynner, but her love life continued well into her 70s. She counted John Wayne, George Bernard Shaw and John F. Kennedy among her conquests. Dietrich maintained her husband and his mistress first in Europe and later on a ranch in the San Fernando Valley, California.In her 60s and 70s, Dietrich's health declined, after a bout with cervical cancer and several stage accidents. She was known to be an alcoholic and became dependent on painkillers. But even after retreating to the privacy of her Paris apartment for the final, mostly bedridden, 11 years of her life, she stayed active politically via telephone, including having had conversations with Ronald Reagan and Mikhail Gorbachev. She also stayed in constant contact with her daughter (her husband had died in the 70s), and with biographer David Bret, with whom she had developed a close relationship and who was one of the only people allowed into her apartment. It is believed that Bret was the last person that Dietrich spoke to, two days prior to her death: "I have called to say that I love you, and now I may die."