William Henry Quilliam was born at 22 Eliot Street, Liverpool, on 10 April 1856, to a wealthy local family. He spent most of his childhood on the Isle of Man and was brought up as a Methodist. He was educated at the Liverpool Institute and the Manx King William's College.
He became a solicitor in 1878, specialising in criminal law, and practising at 28 Church Street, Liverpool. He was described at one point by the Liverpool Weekly Courier as the "unofficial Attorney-General of Liverpool". He defended suspects in many high-profile murder cases. He married Hannah Johnstone in 1879. At this time, Quilliam was also a proponent of the temperance movement in the UK.
Quilliam converted to Islam in 1887 after visiting Morocco to recover from an illness. Quilliam purchased numbers 8, 11 and 12 Brougham Terrace, Liverpool, following his conversion, through a donation from Nasrullah Khan, Crown Prince of Afghanistan. 8 Brougham Terrace became the Liverpool Muslim Institute, the first functioning mosque in Britain. He also opened a boarding school for boys and a day school for girls, as well as an orphanage, Medina House, for non-Muslim parents who could not look after their children but agreed for them to be brought up as Muslims. In addition, the Institute hosted educational classes covering a wide range of subjects, and included a museum and science laboratory. It opened on Christmas Day, 1889.
In 1889, he first published The Faith of Islam, which was concerned with dawah to Islam and its key principles. Initially, 2000 copies were published, but a further 3000 copies were produced in 1890. Quilliam also published The Crescent, a weekly account of Muslims in Britain, and Islamic World, a monthly publication with a worldwide audience. In 1890, Quilliam orchestrated protests against the showing of Hall Caine's play, Mahomet. 1891 saw the first public Muslim burial in Liverpool, of Michael Hall, a former Methodist preacher who converted to Islam.
The 26th and final Ottoman Caliph, Abdul Hamid II, granted Quilliam the title of Sheikh al-Islam for the British Isles. Also, the Emir of Afghanistan recognised him as the Sheikh of Muslims in Britain and he was appointed as Persian Vice Counsel in Liverpool by the Shah.
A number of notables converted to Islam as a result of Quilliam's preaching. They included professors Nasrullah Warren and Haschem Wilde, as well as Resched P. Stanley, the former mayor of Stalybridge. It is estimated that around 600 people converted to Islam in the UK as a direct result of Quilliam's work.
He travelled extensively and received many honours from the leaders of the Islamic world. He had contact with English-speaking West African Muslims and toured the region's coastal cities on his way to Lagos to attend the consecration of the Shitta Bey Mosque in 1894.
Quilliam's work in Liverpool stopped when he left England in 1908 in advance of being struck off as a solicitor. His son swiftly disposed of the property that had been used as a mosque and Islamic centre. Without Quilliam's influence and funding, the Muslim community in Liverpool dispersed.
He had returned to the UK by December 1914 under the name of H. M. Leon. He spent much of his time at Onchan on the Isle of Man. He died in Taviton Street, Bloomsbury, London in 1932, and was buried in Brookwood Cemetery near Woking. The prominent Anglo-Muslims Abdullah Yusuf Ali, Muhammad Marmaduke Pickthall (who each translated the Qur'an), and Lord Headley were later buried near him.
Quilliam argued that Muslims should not fight Muslims on behalf of European powers. He denounced British foreign policy in Sudan and called for a worldwide Caliphate. His political views and allegiance to the Ottoman Caliph led some to denounce him as a traitor.
His legacy is principally maintained by the Abdullah Quilliam Society, which was founded in 1996. The society aims to restore the Liverpool Muslim Institute on Brougham Terrace, and is completing Phases Three and Four of the restoration. The society has been assisted by academics including Ron Geaves, formerly of Liverpool Hope University, and Mehmet Seker of Dokuz Eylül University. The society also offers university student accommodation.
Quilliam, originally The Quilliam Foundation, a think tank aimed at challenging extremist Islamist ideologies, launched in 2008, was named after Abdullah Quilliam.