Who is now world's longest-serving living monarch after Queen Elizabeth II's death?

Bolkiah, who took the throne in 1967, has reigned for 54 years and 339 days (as of Friday) -- more than four years longer than Margrethe II of Denmark, now the second-longest reigning monarch.

Sultan of Brunei Hassanal Bolkiah

The Sultan of Brunei Hassanal Bolkiah became the world's longest serving monarch with the passing of Britain's Queen's Elizabeth II, the media reported.

Bolkiah, who took the throne in 1967, has reigned for 54 years and 339 days (as of Friday) -- more than four years longer than Margrethe II of Denmark, now the second-longest reigning monarch, the Daily Mail reported.