The king has specialized in water management but had to give up all his official duties on his accession to the throne.

CNN: What Dutch 'bicycling monarchs' can teach world's royals

Having made 256 official overseas visits to 129 countries since her accession to the throne in 1952, the Queen would often use her dresses as surreptitious diplomatic tools.

FORBES: She Changes From Day To Day

The monarchy responded with a pragmatic reform programme that began before the accession of King George Tupou V to the throne in September 2006.

ECONOMIST: And of their contrasting attitudes to democratic reform