It's easy to forget how different the rest of the world can be, as well as how much of the present is an odd mix of tradition and contemporary ideology.
Nonetheless, under Sihamoni’s rule, the monarchy as a political institution has effectively ceased to exist.
After last year’s disputed elections, in what would turn out to be one of his biggest political tests, Sihamoni opened parliament despite the opposition Cambodia National Rescue Party – which was boycotting the swearing-in – begging him not to do so.
But the process of de-politicising the monarchy began years earlier.
The power-sharing agreement between the royalist Funcipec party, led by Sihanouk’s second-born son, Prince Norodom Rannariddh, and the Cambodian People’s Party after the 1993 election set the stage for years of political wrangling.
By 2004, Prime Minister Hun Sen had made several threats to abolish the monarchy entirely.
“Anointing Sihamoni made the best of a bad situation,” said journalist Sebastian Strangio, author of the newly released Hun Sen’s Cambodia.
“It secured the monarchy’s survival into an uncertain future, but it also involved giving the CPP what it had always wanted – a figurehead king who would stay within the limits of the constitution."