Saudi King Abdullah Dead: Queen Elizabeth Is Oldest Ruler, Top 6 Oldest Monarchs [PHOTOS]

Saudi Arabia's King Abdullah bin Abdulaziz died at the age of 90 on Friday, leaving behind British Queen Elizabeth II as the oldest living reigning monarch on earth.

The diseased monarch was replaced by Crown Prince Salman, Abdullah's half-brother, the royal court said. Salman, 79, who previously served as defence minister and deputy prime minister of Saudi Arabia, will also be one of the oldest living monarchs in the world, henceforth.

Here is a look at the top oldest living kings, queens and rulers in the world:

Queen Elizabeth II (88)

The British Queen, who is currently 88 and will turn 89 on 21 April this year, is now the oldest living monarch on earth. The queen will also set other records this year. She will mark her 63^rd year on the British throne, one of the longest periods of reign for any king or queen in history. She acceded to the throne when her father King George VI, died in February 1952.

On 10 September, she will surpass her own great-great grandmother, Queen Victoria, as the longest reigning British monarch ever. Victoria had reigned for 63 years and seven months, the record of which will be broken by the present queen in September.

Bhumibol Adulyadej of Thailand (87)

King Bhumibol Adulyadej of Thailand, is the ninth monarch of the Chakri Dynasty. He took to throne on 9 June 1946 and is the world's longest-serving current head of the state and also the longest-reigning monarch in Thai history. He has served for 68 years and still counting.

Although he served for the most number of years as a king, he is the second oldest living monarch. Born on 5 December 1927 he is only one year younger than the British queen.

Sabah Ahmed al-Sabha of Kuwait (85)

Sabah Ahmed al-Sabhh, 85, has ruled Kuwait since 2006 after the previous "Emir" died. He is the 15^th Ruler and 5^th Emir of Kuwait and also the Commander of the Military of Kuwait. He is the fourth son of Kuwait's 10^th ruler, Sheikh Ahmad Al-Jaber Al-Sabah.

He was chosen as the new ruler of the country after the actual Crown Prince of Kuwait, Sheik Saad was deemed unable to rule due to a debilitating disease, widely reported to be Alzheimer's.             

Abdul Halim of Kedah (Malaysia) (87)

Abdul Halim is the 14^th and the current "supreme head of the state" of Malaysia, locally referred to as "Yang di-Pertuan Agong". He is also the 27^th and current Sultan of Kedah. He started his reign on 13 December 2011 and had also served as the fifth ruler from 1970 to 1957.

Born on 28 November 1927, he is only a week older than the world's longest reigning monarch, the king of Thailand.

He is also the first person ever to hold the position of a 'king' twice.

Qaboos bin Said al Said of Oman (74)

The Sultan of Oman, Qaboos bin Said al Said, was born on 18 November 1940 and is one of the oldest living rulers in the world.

He rose to power after he overthrew his own father, Said bin Taimur, in a palace coup in 1970. Having reigned for over 44 years, he is also one of the oldest reigning head of the states on earth.

Queen Margrethe II of Denmark (74)

At the age of 74, the Queen of Denmark, Margrethe II is also one of the oldest reigning monarchs in the world. Having reigned for 43 years now, she is also considered one of the top 10 longest reining monarchs.

Since she was the eldest child of King Frederik IX and Ingrid of Sweden, she succeeded her father in the throne after his death on 14 January 1972.

When she became the Queen, she was the first female monarch of Denmark after Margrethe I who ruled the Scandinavian countries in 1375-1412 during the time of the Kalmar Union – a state that brought together the Scandinavian nations (1397 to 1523).