Wilferd Ferdinand Madelung FBA was a German author and scholar of Islamic history widely recognised for his contributions to the fields of Islamic and Iranian studies. He was appreciated in Iran for his "knowledgeable and fair" treatment of the Shia perspective. In the obituary of the Institute of Ismaili Studies (London) where Madelung worked his last years, it reads: "With particular reference to religious schools and movements in early Islam, his studies, based on a vast array of primary sources, have enriched the discipline’s understanding of almost every major Muslim movement and community – not only early Imami Shi‘ism and the later developments of Twelver, Ismaili and Zaydi Islam but also the lesser known aspects of Sunni, Khariji and the Mu‘tazili schools of theology and philosophy." Madelung died on 9 May 2023 at the age of 92.

Twelver Shīʿism, also known as Imāmiyya, is the largest branch of Shīʿa Islam, comprising about 85 percent of all Shīʿa Muslims. The term Twelver refers to its adherents' belief in twelve divinely ordained leaders, known as the Twelve Imams, and their belief that the last Imam, Imam al-Mahdi, lives in Occultation and will reappear as the promised Mahdi.