He was born Severin Antoniovich Klosowski in Congress Poland on December 14, 1865 and trained as a junior surgeon's assistant before emigrating to London in 1887. He worked as a barber's assistant in the East End, and later took the name George Chapman and ran public houses.
Between 1897 and 1902 three women who lived with him as his wives died: Mary Spink, Bessie Taylor and Maud Marsh. Each declined over weeks with vomiting and wasting that doctors recorded as consumption or gastric illness. He nursed them attentively throughout, and he inherited or took what they had. He had used tartar emetic, an antimony compound, which he bought in quantity and which was untraceable to anyone not looking for it.
Maud Marsh's parents were not satisfied. Her father called in his own doctor, who suspected poisoning, and after her death in October 1902 an analysis found antimony. Spink and Taylor were exhumed, and antimony preserves tissue. The bodies were found remarkably intact, which made the analysis straightforward. He was arrested on October 25, 1902.
He was tried at the Old Bailey in March 1903, convicted of Maud Marsh's murder, and hanged at Wandsworth on April 7, 1903.
Inspector Frederick Abberline, who had led the Whitechapel investigation in 1888, said on Chapman's arrest that he believed he had caught the Ripper. Klosowski was living in Whitechapel at the relevant time, which is the whole of the basis for it. There is no evidence connecting him to those killings, and the change of method, from mutilation of strangers in the street to slow poisoning of women he lived with, is the standard objection. The entry records the claim because Abberline made it, and records that it has never been supported.