Oman’s Sultan Qaboos bin Said, one of West Asia’s longest serving rulers who maintained the country’s neutrality in regional struggles, died on Friday and his cousin Haitham bin Tariq al-Said was named as his successor in a smooth transition.

With his death, the region loses a trusted and seasoned leader, seen as the father of modern Oman, who balanced ties between two neighbours locked in a regional struggle, Saudi Arabia to the west and Iran to the north, as well as the US.

In a televised speech, Haitham promised to uphold Muscat’s policy of peaceful coexistence and friendly relations with all nations while further developing Oman. “We will continue to assist in resolving disputes peacefully,” he said.

Oman and fellow Gulf states declared three days of official mourning with flags to be flown at half-mast for the Western-backed Qaboos, 79, who ruled since taking over in a bloodless coup in 1970 with the help of former colonial power Britain.

His funeral procession passed along Muscat’s main road amid tight security as Omanis thronged the palm tree-lined route, some reaching out their hands and others taking pictures.

The casket, draped in the Omani flag, was carried into Sultan Qaboos Grand Mosque where hundreds joined prayers inside. Haitham stood facing the casket, with the traditional curved dagger, or khanjar, strapped to his waist. Qaboos was later buried in a family cemetery.

Omanis took to social media to mourn the death of a ruler who had made regular tours of the country.

“The first words I heard from my weeping mother after news of the great Sultan Qaboos’ death was: The father of orphans, of the poor, of the downtrodden, of all of us, has died,” Twitter user Abdullah bin Hamad al-Harthi wrote.