Sheikh (Sufism) in the context of "Imam Shamil"

Imam Shamil (Arabic: الشيخ شامل, romanized: al-Šaykh Šāmil; Avar: Шейх Шамил, romanized: Sheykh Shamil; Chechen: имам Шемал, romanized: imam Shemal; Kumyk: Шамил, romanized: Şamil; Russian: Имам Шамиль; 26 June 1797 – 4 February 1871) was the political, military, and spiritual leader of North Caucasian resistance to Imperial Russia in the 1800s, the third Imam of the Caucasian Imamate (1840–1859), and a Sunni Muslim sheikh of the Naqshbandi Sufis.