Sultan Qaboos of Oman has returning home after traveling to Belgium for a medical check-up. Sultan Qaboos, who ruled Oman for almost half a century, has died at the age of 79. AP
Omani leader Sultan Qaboos bin Said attends the opening of the Gulf Cooperation Council summit in 2007. AFP
Oman's Sultan Qaboos walks with UAE President Sheikh Zayed in Sohar, Oman, in 1999. Wam / AFP
Sheikh Mohamed bin Zayed, Crown Prince of Abu Dhabi Deputy Supreme Commander of the UAE Armed Forces, left, meets with Sultan Qaboos bin Said, Sultan of Oman, during an official visit to Oman in 2013. Ryan Carter / Crown Prince Court - Abu Dhabi
United Arab Emirates's President and Ruler of Abu Dhabi Sheikh Khalifa bin Zayed, right, walks with Oman's leader Sultan Qaboos bin Said upon his arrival to Al Ain Airport in 2011. Wam
Sheikh Mohammed Bin Rashid and Sultan Qaboos bin Said of Oman held talks on bilateral ties at the Zabeel Palace in Dubai in 2012. Wam
Sultan Qaboos bin Said in 1975. AP Photo
Oman's Sultan Qaboos Bin Said is pictured during a cabinet meeting at the royal palace in Muscat. Sultan Qaboos, who ruled Oman for almost half a century, has died at the age of 79. AFP
Oman's Sultan Qaboos bin Said welcomes Britain's Queen Elizabeth II upon her arrival at Muscat in 2010. Sultan Qaboos, who ruled Oman for almost half a century, has died at the age of 79. AFP
Jordan's King Abdullah welcomes Sultan Qaboos of Oman on his arrival at Aqaba airport in 1999. Reuters
Sultan Qaboos of Oman escorts US President Bill Clinton upon his arrival to Oman airport. Sultan Qaboos, who ruled Oman for almost half a century, has died at the age of 79. AFP
Sultan Qaboos bin Said greets French President Nicolas Sarkozy upon his arrival in Muscat. Sultan Qaboos, who ruled Oman for almost half a century, has died at the age of 79. AFP
The US Secretary of State Mike Pompeo with Oman's Sultan Qaboos during a recent visit to Muscat. Sultan Qaboos, who ruled Oman for almost half a century, has died at the age of 79. AP
Sultan Qaboos Bin Said of Oman attending the country's National Day in Muscat. Sultan Qaboos, who ruled Oman for almost half a century, has died at the age of 79. AFP
Portrait of Qaboos Bin Said Al Said, the Sultan of Muscat and Oman, in military uniform, circa 1970. Sultan Qaboos, who ruled Oman for almost half a century, has died at the age of 79. Getty Images
Omani Sultan Qaboos greets South African President Nelson Mandela in 1999 upon his arrival in Muscat at the start of a short tour of the Gulf to promote investments in South Africa. Sultan Qaboos, who ruled Oman for almost half a century, has died at the age of 79. AFP
Queen Elizabeth II walks with the Sultan of Oman, His Majesty Qaboos bin Said Al Said, after arriving in Muscat, Oman in 2010. Sultan Qaboos, who ruled Oman for almost half a century, has died at the age of 79. Getty Images
Sultan Qaboos of Oman has returning home after traveling to Belgium for a medical check-up. Sultan Qaboos, who ruled Oman for almost half a century, has died at the age of 79. AP
Omani leader Sultan Qaboos bin Said attends the opening of the Gulf Cooperation Council summit in 2007. AFP
Oman's Sultan Qaboos walks with UAE President Sheikh Zayed in Sohar, Oman, in 1999. Wam / AFP
Sheikh Mohamed bin Zayed, Crown Prince of Abu Dhabi Deputy Supreme Commander of the UAE Armed Forces, left, meets with Sultan Qaboos bin Said, Sultan of Oman, during an official visit to Oman in 2013. Ryan Carter / Crown Prince Court - Abu Dhabi
United Arab Emirates's President and Ruler of Abu Dhabi Sheikh Khalifa bin Zayed, right, walks with Oman's leader Sultan Qaboos bin Said upon his arrival to Al Ain Airport in 2011. Wam
Sheikh Mohammed Bin Rashid and Sultan Qaboos bin Said of Oman held talks on bilateral ties at the Zabeel Palace in Dubai in 2012. Wam
Sultan Qaboos bin Said in 1975. AP Photo
Oman's Sultan Qaboos Bin Said is pictured during a cabinet meeting at the royal palace in Muscat. Sultan Qaboos, who ruled Oman for almost half a century, has died at the age of 79. AFP
Oman's Sultan Qaboos bin Said welcomes Britain's Queen Elizabeth II upon her arrival at Muscat in 2010. Sultan Qaboos, who ruled Oman for almost half a century, has died at the age of 79. AFP
Jordan's King Abdullah welcomes Sultan Qaboos of Oman on his arrival at Aqaba airport in 1999. Reuters
Sultan Qaboos of Oman escorts US President Bill Clinton upon his arrival to Oman airport. Sultan Qaboos, who ruled Oman for almost half a century, has died at the age of 79. AFP
Sultan Qaboos bin Said greets French President Nicolas Sarkozy upon his arrival in Muscat. Sultan Qaboos, who ruled Oman for almost half a century, has died at the age of 79. AFP
The US Secretary of State Mike Pompeo with Oman's Sultan Qaboos during a recent visit to Muscat. Sultan Qaboos, who ruled Oman for almost half a century, has died at the age of 79. AP
Sultan Qaboos Bin Said of Oman attending the country's National Day in Muscat. Sultan Qaboos, who ruled Oman for almost half a century, has died at the age of 79. AFP
Portrait of Qaboos Bin Said Al Said, the Sultan of Muscat and Oman, in military uniform, circa 1970. Sultan Qaboos, who ruled Oman for almost half a century, has died at the age of 79. Getty Images
Omani Sultan Qaboos greets South African President Nelson Mandela in 1999 upon his arrival in Muscat at the start of a short tour of the Gulf to promote investments in South Africa. Sultan Qaboos, who ruled Oman for almost half a century, has died at the age of 79. AFP
Queen Elizabeth II walks with the Sultan of Oman, His Majesty Qaboos bin Said Al Said, after arriving in Muscat, Oman in 2010. Sultan Qaboos, who ruled Oman for almost half a century, has died at the age of 79. Getty Images
Sultan Qaboos of Oman has returning home after traveling to Belgium for a medical check-up. Sultan Qaboos, who ruled Oman for almost half a century, has died at the age of 79. AP
Sultan Qaboos of Oman dies aged 79
Three days of official mourning in Oman and the UAE after the longest ruling leader in the Middle East passes away