Boris Johnson and Prince Charles have arrived in Oman as the country mourns the death of its former ruler Sultan Qaboos bin Said.

The prime minister and the royal will both attend a condolence ceremony in Muscat for the Middle East’s longest ruling monarch, who died over the weekend.

Mr Johnson will also join other global figures in meeting his successor, Sultan Haitham bin Tariq Al Said.

Kuwait's emir, Bahrain’s king and Nicolas Sarkozy​, the former French president, have travelled to Oman to meet the new leader as the country prepares for three days of official condolences.

Some of those who have arrived to pay their respects are currently at odds with each other, such as the rulers of Qatar and the United Arab Emirates.

Scars on Middle East landscape bear witness to past peace failures Show all 16 1 /16 Scars on Middle East landscape bear witness to past peace failures Scars on Middle East landscape bear witness to past peace failures A Syrian tank lies turned over in the Hermon Stream in the Banias Nature Reserve on the western edge of the Israeli-occupied Golan Heights. Israel captured the area, a former demilitarized zone, in the 1967 Six Day War Reuters Scars on Middle East landscape bear witness to past peace failures A part of the trench in a former Jordanian military post known as Ammunition Hill in Jerusalem. Originally built by the British, the site was captured by Jordan in the 1948-1949 war and held by them until Israeli troops captured it in the 1967 Reuters/Ronen Zvulun Scars on Middle East landscape bear witness to past peace failures An abandoned mosque on a rainy morning in the Golan Heights, in territory that Israel captured from Syria and occupied in the 1967 Middle East war. Until 1967 a Syrian village inhabited by Circassians stood near the site, which now lies just 5km on the Israeli side of the United Nations-monitored 'Area of Separation' that divides Israeli and Syrian military forces under a 1974 ceasefire arrangement Reuters/Ronen Zvulun Scars on Middle East landscape bear witness to past peace failures The broken helicopter of the late Palestinian Authority President Yasser Arafat sits atop a structure in Gaza City. Without its main rotor, it is now on public display in the coastal enclave that is now controlled by the Palestinian Authority's most powerful domestic rival, Hamas Reuters/Ibraheem Abu Mustafa Scars on Middle East landscape bear witness to past peace failures A sign warning of landmines on a fence in the Golan Heights. Many Israeli and foreign tourists drive past the site on their way to popular holiday spots Reuters/Ronen Zvulun Scars on Middle East landscape bear witness to past peace failures Part of an abandoned Syrian building in the Golan Heights. Once a military headquarters, it is one of many Syrian buildings left deserted and abandoned since wars fought half a century ago Reuters/Ronen Zvulun Scars on Middle East landscape bear witness to past peace failures The wall of a structure in a former Syrian outpost in the Israeli-occupied Golan Heights. In stark contrast to the beauty of the surrounding countryside, it is now crumbling and covered in graffiti, one Arabic message reading: "The Syrian army passed by here." Reuters/Ronen Zvulun Scars on Middle East landscape bear witness to past peace failures Buildings constructed during the British Mandate era to serve as jails and fortified positions in Al-Jiftlik village near Jericho, in the Israeli-occupied West Bank. Long abandoned, sheep now wander through the empty buildings, searching for vegetation in the scorching heat of the Jordan Valley. The Israeli military sometimes uses them for training, Palestinian residents say Reuters/Mohamad Torokman Scars on Middle East landscape bear witness to past peace failures A bunker in the Golan Heights, in territory that Israel captured from Syria. It was used for military purposes and has been deserted for many years Reuters/Ronen Zvulun Scars on Middle East landscape bear witness to past peace failures British soldiers depicted in a mural on an old pillbox in Jerusalem. The pillbox dating back to the era of British Mandatory rule before 1948, stands abandoned in a busy intersection of Jerusalem. The mural was added in recent years Reuters/Ronen Zvulun Scars on Middle East landscape bear witness to past peace failures Concrete blast walls are seen in an open area once used by the Israeli military near Rahat, southern Israel. Once part of a facility for training in urban warfare, the barriers are now an isolated scar on the landscape Reuters/Ronen Zvulun Scars on Middle East landscape bear witness to past peace failures A part of a trench is seen in a former Jordanian military post known as Ammunition Hill in Jerusalem. Originally built by the British, the site was captured by Jordan in the 1948-1949 war and held by them until Israeli troops captured it in the 1967 Reuters/Ronen Zvulun Scars on Middle East landscape bear witness to past peace failures The derelict remains of Gaza International Airport in Rafah in the southern Gaza Strip. Former US President Bill Clinton attended the opening ceremony in 1998. But Israeli air strikes and bulldozers closed it down during the second Palestinian uprising, or Intifada, a few months after the September 11, 2001 attacks on the United States Reuters/Ibraheem Abu Mustafa Scars on Middle East landscape bear witness to past peace failures A house is seen in Lifta, a ruined Palestinian Arab village whose inhabitants left or were forced from their homes in the conflict that accompanied the end of British rule and the founding of Israel in 1948. The abandoned ruins are visible to travelers arriving at the western entrance of Jerusalem Reuters/Ronen Zvulun Scars on Middle East landscape bear witness to past peace failures An abandoned mosque on a rainy morning in the Golan Heights, in territory that Israel captured from Syria Reuters/Ronen Zvulun Scars on Middle East landscape bear witness to past peace failures A part of a structure in a former Jordanian military base near the Dead Sea in the Israeli-occupied West Bank. The building is a scar in the landscape as it stands deserted following the 1967 Middle East war when Israel captured the area from the Jordanians Reuters/Ronen Zvulun

Iran’s foreign minister, Mohammad Javad Zarif, has also visited.

Sultan Haitham, who was the culture minister, has pledged to follow his predecessor’s example of promoting peace and dialogue in the Middle East.

Oman has also served as an interlocutor between Iran and the US, which are facing a level of unprecedented tension.

The UK prime minister called former leader Qaboos “an exceptionally wise and respected leader who will be missed enormously" after news of his death broke.

“He leaves a profound legacy, not only in Oman but across the region too,” Mr Johnson said.

Qaboos ruled the small Gulf nation for nearly five decades after toppling his father as ruler in a coup.

He died on Saturday from an undisclosed illness he had been battling for years.