Thousands of mourners attended the funeral Sunday for the Emir of Kuwait, Sheikh Jaber Al-Ahmed Al-Sabah, who died at age 79.

Kuwait has now begun a 40-day period of mourning.

Jaber had ruled as the 13th emir of Kuwait since Dec. 31, 1977.

The body of Sheikh Jaber Al-Ahmed Al-Sabah is carried for burial at Sulaibikhat cemetery in Kuwait City, Kuwait on Sunday. (AP Photo)

He'd been ailing since suffering a brain hemorrhage five years ago and, upon his death which was announced on state television – was succeeded by Crown Prince Sheik Saad Al Abdullah Al Sabah.

Sabah is said to be in his mid-70s and is also in poor health. He attended Sunday's funeral using a wheelchair.

The emir's body was brought to the cemetery wrapped in the Kuwaiti flag. He was buried in an unmarked grave with members of the ruling family standing by and raising their hands in prayer.

Sheikh Jaber Al-Ahmed Al-Sabah, left, stands besides Sheik Saad Al Abdullah Al Sabah, right, in this October 2002 photo. (AP Photo)

Those attending the funeral included Jordan's King Abdullah.

"The Arab and Islamic nations have lost a wise leader who consecrated his life to the service of his country, his Arab nation and the Islamic nation," said Arab League Secretary-General Amr Moussa in a statement.

For nearly 250 years, the al-Sabah family has ruled the Middle Eastern country, which borders the Persian Gulf between Iraq and Saudi Arabia.

It is nominally a constitutional monarchy, but both the country's prime minister and deputy prime minister are appointed by the emir.

The cabinet is appointed by the prime minister from an elected National Assembly, but must also be approved by the emir.

Since the fall of Saddam Hussein in Iraq in 2003, Kuwait's ruling family had come under increasing pressure to share power.

The country consists of only 17,820 square kilometres and about 2.3 million people, but it casts a bigger shadow on the international stage because it sits on about one-tenth of the world's crude oil reserves.

Used as the main launchpad for the U.S.-led invasion of Iraq in 2003, Kuwait hosts up to 30,000 U.S. troops and some 13,000 U.S. citizens live in the country.