Henri Désiré Landru (12 April 1869 – 25 February 1922) was a French serial killer and real-life "Bluebeard".
Landru was born in Paris. After leaving school, he spent four years in the French Army from 1887 – 1891. After he was discharged from service, he proceeded to have a sexual relationship with his cousin. She bore him a daughter, although Landru did not marry her; he married another woman two years later and had four children. He was shortly swindled out of money by a fraudulent employer. He turned to fraud himself, operating scams that usually involved swindling elderly widows. He was sentenced to two years imprisonment in 1900 after being arrested and found guilty of fraud, the first of several such convictions. By 1914, Landru was estranged from his wife and working as a second-hand furniture dealer.
Landru began to put advertisements in the lonely hearts sections in Paris newspapers, usually along the lines of "Widower with two children, aged 43, with comfortable income, serious and moving in good society, desires to meet widow with a view to matrimony." With World War I underway, many men were being killed in the trenches, leaving plenty of widows upon whom Landru could prey.