[from p563 B. Guinness Orchard, Liverpool's Legion of Honour, Birkenhead, 1893]
Note strictly Manx but an interesting character.
QULLIAM (Wm. HENRY), of 21 Fairfield-crescent, Fairfield, "our Mahomedan solicitor," is a son of a watch manufacturer who was in a large way of business, and whose other children still carry it on at 32 Elizabeth-street, Liverpool. As a youth he was much among Wesleyans, but afterwards attended the ministry of the late Rev Charles Beard, a famous Unitarian. When about seventeen, however, being sent to Algeria for his health's sake, he became interested in Mahomedanism to so great a degree that ultimately he became a convert, and has remained a Mahomedan, anxious and zealous to propagate that creed in his native country. Mr. Quilliam is a solicitor, with an office at 15 Manchester-street, near the Police Courts, where he is in large practice, popular in certain classes of society as an advocate who represents his clients' cause as earnestly and fearlessly as if it were his own. Through his exertions a Mahomedan Mosque has been added to the various other peculiar places of worship in Liverpool, and there he is in the habit of publicly explaining the beliefs and usages of this religion. The Mahomedan Mosque is in West Derby-road. In 1891 he visited Constantinople with his son, whom he is educating in the faith of Islam, when they were received with special favour by its chiefs, and admitted to an audience by the Sultan, who afterwards sent Mr. Quilliam some valuable presents.
See also tale retold by Lamothe. and quote from Porcupine Magazine. The descent from Lt John Quilliam of Victory fame is almost certainly untrue - John Quilliam had no known children.
W H Quilliam is son of Liverpool-born Robert Henry Quilliam and Harriet Burrows, R.H. Quilliam is mostly likely son of Liverpool-born Samuel Quilliam who is probably the son of Robert Quilliam and Ann Winn (birth 14 Dec & ch 27 Dec 1809 St Nicholas, Liverpool) - it is just possible that this Robert is the youngest brother of John Quilliam.
The Mosque is now a registry office - although W. H. Quilliam gathered a sizeable congregation, including many converts, it seems they soon drifted apart when he moved away from Liverpool in 1908.