[a] One of their most visible legacies is the Bahla Fort, a large complex of mud brick buildings on stone foundations built from the 12th to the 15th century.

After the early days of Islam, the tribes in the interior of Oman were led by Imams, who held both spiritual and temporal power.

[3] They established a system where the ulama of the Banu Sama, the largest of the Nizari tribes of the interior, would select the Imam.

[7] The Banu Nabhan controlled the trade in frankincense on the overland route via Sohar to the Yabrin oasis, and then north to Bahrain, Baghdad and Damascus.

[11] There are records of personal visits by Nabhani rulers to Ethiopia, Zanzibar, the Lamu Archipelago of what is now Kenya, and Persia.

[15] In 1507 the Portuguese captured the coastal city of Muscat, and gradually extended their control along the coast up to Sohar in the north and down to Sur in the southeast.

[12] Omani histories record that the Bahla fort was destroyed in the early 17th century shortly before the Ya'Aruba dynasty took control of Oman, although it is possible that parts of the old structure remained and were used as the basis for later construction.

[4] The Nabahina retained power at the beginning of the Ya'rubi state and they treated Jabal al-akhdar (The Green Mountains located in the interior of Oman) as an emirate.

[17] At the time the Sheikh of the Bani Riyam was Suleiman bin Himyar Al-Nabhani, Lord of the Jebel Akhdar-and descendant of the ancient Nabahina dynasty.

The ahl al-hal wal ‘aqd are the leading personalities of society who are knowledgeable and have a proven track record of sincerity and sacrifice.