Yahya Muhammad Hamid ed-Din

Yahya Muhammad Hamidaddin (or Imam Yahya) (1869—1948) became imam of the Zaydis in 1904 and king of Yemen in 1926. His name in full was H.M. Amir al-Mumenin al-Mutawakkil 'Ala Allah Rab ul-Alamin Imam Yahya bin al-Mansur Bi'llah Muhammad Hamidaddin, Imam and Commander of the Faithful, and King of the Yemen. He died during an unsuccessful coup attempt in 1948 and was succeeded by his son Imam Ahmad.

Yahya Muhammad Hamidaddin was born into the Hamidaddin branch of the al-Qasimi dynasty. Upon the death of his father in 1904, Yahya became Imam, effectively ruler over the mountainous areas of the future North Yemen. However the Ottomans who made claim on the area didn't recognize his rule, with war as result. The war against the Ottomans came to an end in 1911, and his rule over North Yemen was recognized. Yahya became a loyal subject to the empire.

Following the end of World War I in 1918, the Ottomans lost control over North Yemen, and Yahya became the ruler of the new independent state. There was another war, this time with the House of Saud, in 1934. Yahya's forces were badly defeated, but king Ibn Saud offered him peace without making territorial concessions. In 1946 opposition to Yahya's regime became organized. Imam Yahya Muhammad Hamidaddin was shot and killed on February 17 1948, and was succeeded by his son Ahmad bin Yahya.

His Qurayshi descent and vast canonical knowledge also meant he was proposed as a khalifa by the Islamic scholar Mohammad Rashid Rida following the abolition of the Caliphate in Turkey. This was only the second time a Shia imam was proposed as a khalifa; the first being the twelver imam Ali al-Rida, who was nominated by Khalifa Al Mamun in the 9th century.