Friedrich Engels in London

In 1870, Engels moved to London where he and Marx lived until Marx's death in 1883. His London home during this period and until his death was 122 Regent's Park Road, Primrose Hill, NW1. Marx's first London residence was a cramped apartment at 28 Dean Street,Soho. From 1856, he lived at 9 Grafton Terrace, Kentish Town, and then in a tenement at 41 Maitland Park Road from 1875 until his death.

Mary Burns suddenly died of a heart disease in 1863, after which Engels became close with her younger sister Lydia ("Lizzie"). They lived openly as a couple in London and married on 11 September 1878, hours before Lizzie's death

Mary Burns (1823 – 7 January 1863) was a working-class Irish woman, best known as the lifelong partner of Friedrich Engels.

Burns lived in Salford, near Manchester, England. She met Engels during his first stay in Manchester, probably early 1843. It is likely that Burns guided Engels through the region, showing him the worst districts of Salford and Manchester for his research.

Mary Burns was the daughter of Michael Burns or Byrne, a dyer in a cotton mill, and of Mary Conroy. The family may have lived off Deansgate. She had a younger sister named Lydia (1827–1878), known as “Lizzie", and a niece named Mary Ellen Burns (born 1859), known as "Pumps".

After meeting in the 1840s, Burns and Engels formed a relationship that lasted until Burns' sudden death at the age of 41 on 7 January 1863. Although the custom of the day was marriage, the two were politically opposed to the bourgeois institution of marriage and never married. After her death Engels lived with her sister Lizzie, whom he married on 11 September 1878, hours before her death.

Not much is written about Mary Burns. The only direct references to Mary Burns that survived, is a letter from Marx to Engels on learning of her death saying she was "very good natured" and "witty", and a letter from Marx's daughter, Eleanor, saying she was "very pretty, witty and an altogether charming girl, but in later years drank to excess."

Lydia "Lizzie" Burns (1827 – 12 September 1878) was a working-class Irish woman, best known as a long-term partner and wife ofFriedrich Engels.

Lizzie Burns was a daughter of Michael Burns or Byrne, a dyer in a cotton mill, and of Mary Conroy. The family may have lived off Deansgate. Her mother died in 1835, and her father remarried a year later.

Lizzie had an elder sister Mary (1823–1863), a lifelong partner of Engels until her sudden death of a heart disease. Mary Burns and Engels considered marriage a bourgeois institution and never married. In the 1850s, when Mary Burns and Engels lived in Ardwick, Lizzie stayed with them as a housekeeper, and after her sister's death eventually became Engels' partner. In the 1870s they lived openly as a couple in London, with Lizzie's niece, Mary Ellen (known as Pumps), as a housekeeper.

Both Lizzie and her sister were known as formally illiterate yet intelligent women, with strong working-class ties. They showed Engels the actual conditions of the factory employers in Britain. Eleanor Marx ( Jenny Julia Eleanor "Tussy" Marx, was the English-born youngest daughter of Karl Marx. She was herself a socialist activist, who sometimes worked as a literary translator. In March 1898, after discovering that her partner and prominent British Marxist, Edward Aveling, had secretly married a young actress in June the previous year, she committed suicide by poison. She was 43.)

wrote that

[Lizzie] was illiterate and could not read or write but she was true, honest and in some ways as fine-souled a woman as you could meet.

In early September 1878 Burns fell seriously ill with some kind of tumor, and to please her religious beliefs, Engels married her. She died hours later. Her death made a strong impression on Engels. He later wrote about her:

My wife was a real child of the Irish proletariat and her passionate devotion to the class in which she was born was worth much more to me – and helped me more in times of stress – than all the elegance of an educated, artistic middle-class bluestocking.