Nizari Isma'ilism (Arabic: النزارية, romanized: al-Nizāriyya) are the largest segment of the Ismaili Muslims, who are the second-largest branch of Shia Islam after the Twelvers.[1] Nizari teachings emphasize independent reasoning or ijtihad; pluralism—the acceptance of racial, ethnic, cultural and inter-religious differences; and social justice.[2] Nizaris, along with Twelvers, adhere to the Jaʽfari school of jurisprudence.[3] The Aga Khan, currently Aga Khan IV, is the spiritual leader and Imam of the Nizaris. The global seat of the Ismaili Imamate is in Lisbon, Portugal.