Mustapha Karsa (pictured circa 1900) was born in Damascus in around 1848 to a wealthy landowning family. In 1880-1, Karsa came to Manchester to develop the family's textile business, leaving his first wife and their children behind in Syria. He settled in Chorlton-cum-Medlock, lodging with a Jewish clerk from Beirut. He met and married Helen Saunders (1870-1939) under Islamic law and had eight children by her. They would later travel to Beirut to register their Islamic union formally but in Manchester, Helen insisted that the children were all baptized as Anglicans. The Karsas settled in Sale, first at 71 Broad Road and later to a larger residence, "The Sycamores" on Wardle Rd; neither house has survived. Sale was by that time the suburb of choice for Manchester's well-to-do merchants, and Karsa was one of them, enjoying great success with his textile business, which developed branches in Izmir, Alexandria, Smyrna and Beirut. In 1903, Karsa was appointed the Ottoman Consul for Manchester, and he would often provide accommodation for other Ottoman officials at the Sycamores like Kiamil Bey, the Ottoman Consul for Liverpool, and Faid Ibrahim, the First Secretary to the Imperial Ottoman Embassy. Karsa presented himself as an Anglicized, assimilated Muslim, but one who remained faithful at heart. He remained Consul until his death in 1907.

As his second wife under Islamic rites, Helen relocated to Beirut with her five youngest children after Karsa's death. Her daughter, Emimie (Amina) married into a wealthy Beirut family, the Ardatis. Helen's oldest son, Cecil Mustapha, continued the family business in Manchester. Cecil married the daughter of a bristle manufacturer at a local Wesleyan chapel, and had two sons, Anthony and Joseph. He gave distinguished service to the Royal Garrison Artillery during the First World War for which he was given a medal. He continued the family business thereafter and died in 1951. He was given a Muslim burial (janaza) at the Victoria Park Mosque in Rusholme, Manchester, which had opened three years previously. Cecil's youngest sister, Fizie, joined him from Beirut and was also buried like him by the Victoria Park Mosque. Another sister, Lily married a Christian merchant, Alexander Hamrah, from a Beirut family who had settled in New York, and they had six children, Elias, Edna, Alice, Claire, Louise and George.

Karsa took a third wife, Beatrice, whom he married under Islamic rites in Liverpool, but she charged him for breach of promise in court, claiming that she hadn't known he was already married. As he couldn't defend polygamy in an English legal setting, he had to deny he had proposed to her. He was found guilty and fined £200.

Some 24 Syrian Muslim visitors are mentioned in the pages of the Liverpool Muslim Institute's weekly newspaper, the Crescent (see picture with some of them with Quilliam and Karsa sat next to each other in the centre). After the Liverpool Muslim Institute was recognised by the Ottomans in 1890, it gained the support of the Ottoman Muslim citizens in Manchester who had set up textile trading businesses there. Karsa and his wife Helen hastened to sign the Institute's Book of Allegiance and did so in 1891. Karsa was the eight born Muslim to sign the register, and Helen was the 29th convert to do so. Karsa became an honorary vice-president of the Institute until his death and he contributed generously to it. The Karsas became close to the Quilliams, visiting them on the Isle of Man during their summer vacations. The Quilliams returned the favour by visiting Karsa family members when passing through Smyrna on their way to Istanbul. Like the other Syrian Muslims, Karsa would travel to Liverpool to attend the Eid prayers, the Mawlid, the celebration of the Sultan's birthday, and he also attended upon Ottoman officials who were passing through Liverpool en route to some other destination, who would stop by the mosque while in port. Riordan Macnamara suggests that Quilliam gained the loyalty of these Syrian Muslim traders because they regarded him as a fellow Ottoman notable, as someone who had his own status in society and who enjoyed the favour of the Ottoman authorities.

The large house where the Karsas lived in 1901, the Sycamores, on Wardle Road in Sale, no longer exists, but its original location is marked on the map above. The 1901 Census lists the family and their two distinguished visitors in the following way:

Mustapha Karsa, 53, cotton merchant, b. Damascus (Turkish subject), 

Helen Karsa, wife, 31, b. Manchester

Mustapha, son, 12, b. Cheshire, Sale

Emimie, dau, 9, b. Cheshire, Sale

Rudah, son, 8, b. Cheshire, Sale

Yuseph, son, 6, b. Cheshire, Sale

Filzie, dau, 1, b. Cheshire, Sale

Kamiel, son, 4 months, b. Cheshire, Sale

Kamiel Bey, visitor, married, 33, Consul [for Liverpool] to the Imperial Ottoman [Domains]

Faid Ibrahim, visitor, single, 34, First Secretary to the Imperial Ottoman Embassy

+ Four domestic servants