“With hearts steadfast in faith in God’s decree and destiny, the Bureau of the Emir mourns the great loss to the nation of the late — may God have mercy on him — His Highness the Father Amir Sheikh Hamad bin Khalifa Al Thani,” read a statement published by the emir’s office on social media.
The former leader was seen as one of the key architects of modern Qatar and led the country during a period of rapid economic growth.
Sheikh Hamad took power in June 1995, overthrowing his father in a bloodless coup while the latter was abroad.
He inherited a small, largely marginal emirate with nearly empty coffers and transformed it into a major player on the regional and international stage.
During his time in office, the international broadcaster Al Jazeera was launched in 1996, following a decree issued by the emir.
In June 2013, Sheikh Hamad surprised many by voluntarily abdicating in favour of his son, Sheikh Tamim bin Hamad Al Thani, a first in the recent history of the Arab world.
Qatar is one of the smallest Arab states with a population of around 3 million people, most of whom are foreign workers.
The country was a British protectorate for 55 years until 1971.
It has been ruled by a monarchy, the Al Thani family, since the mid-19th century.