When Can There Be More Than One Imam?

Imām Aḥmad ibn Yaḥyā ibn al-Murtaḍā (d. 840 AH / 1437 CE) explains in his encyclopedic work al-Baḥr al-Zakhkhār al-Jāmiʿ li-Madhāhib ʿUlamāʾ al-Amṣār, under the chapter on International Relations and Military Conduct (Kitāb al-Siyar), that it is considered permissible for more than one imam (leader) to exist in different and distant lands when this serves the greater benefit (maṣlaḥa).

He records the scholarly consensus on the prohibition of multiple imams within the same locality, while also noting its permissibility in faraway regions.

To illustrate, he cites a report from Imām Nāṣir al-Aṭrūsh (d. 304 AH), who said:

“Those in our region answer our summons, and those in the region of Imām Yaḥyā al-Hādī (d. 298 AH) answer his.”