Abu Talib Yahya was an imam

Imam

An imam is an Islamic leadership position, often the worship leader of a mosque and the Muslim community. Similar to spiritual leaders, the imam is the one who leads Islamic worship services. More often, the community turns to the mosque imam if they have a religious question...

 of the Zaydiyyah sect in 1020-1033.

Like his elder brother and predecessor al-Mu'ayyad Ahmad

Al-Mu'ayyad Ahmad

Al-Mu'ayyad Ahmad was an imam of the Zaydiyyah sect.Al-Mu'ayyad Ahmad's ancestor in the tenth degree was the Twelver imam Hasan bin Ali. He was a disciple of Abu Abdallah al-Basri and the qa'i Abd al-Jabbar, and a learned expert on the Ahl al-Bayt concept...

, Abu Talib Yahya was a prominent man of learning and a descendant of the Twelver imam

Twelve Imams

The Twelve Imams are the spiritual and political successors to Muhammad, the Prophet of Islam, in the Twelver or Ithna-‘ashariyyah branch of Shī‘ah Islam....

 Hasan bin Ali. He succeeded al-Mu'ayyad Ahmad in the imamate of the Zaidi territories in Gilan

Gilan Province

Gilan Province is one of the 31 provinces of Iran. It lies along the Caspian Sea, just west of the province of Mazandaran, east of the province of Ardabil, north of the provinces of Zanjan and Qazvin....

 and Deylaman

Dailamites

The Daylamites or Dailamites were an Iranian people inhabiting the mountainous regions of northern Iran on the southern shore of the Caspian Sea. They were employed as soldiers from the time of the Sassanid Empire, and long resisted the Arab conquest of Iran and subsequent Islamization...

 in Persia, formally as "caliph

Caliph

The Caliph is the head of state in a Caliphate, and the title for the ruler of the Islamic Ummah, an Islamic community ruled by the Shari'ah. It is a transcribed version of the Arabic word   which means "successor" or "representative"...

". At this time there were two major Zaidi

Zaidiyyah

Zaidiyya, or Zaidism is a Shi'a Muslim school of thought named after Zayd ibn ʻAlī, the grandson of Husayn ibn ʻAlī. Followers of the Zaydi Islamic jurisprudence are called Zaydi Shi'a...

 territories, namely the area south of the Caspian Sea

Caspian Sea

The Caspian Sea is the largest enclosed body of water on Earth by area, variously classed as the world's largest lake or a full-fledged sea. The sea has a surface area of and a volume of...

 and the highlands of Yemen

Yemen

The Republic of Yemen , commonly known as Yemen , is a country located in the Middle East, occupying the southwestern to southern end of the Arabian Peninsula. It is bordered by Saudi Arabia to the north, the Red Sea to the west, and Oman to the east....

. For many years after the death of imam al-Mahdi al-Husayn

Al-Mahdi al-Husayn

al-Mahdi al-Husayn was an imam of the Zaidi state in Yemen who claimed power in the years 1003-1013, in rivalry with another imam....

 in 1013, no local imam was appointed in the Yemeni territory. In Zaidi historiography

Historiography

Historiography refers either to the study of the history and methodology of history as a discipline, or to a body of historical work on a specialized topic...

, al-Mu'ayyad Ahmad and Abu Talib Yahya are sometimes listed as such, although they never visited Yemen.