What countries are kingdoms?

Absolute:

Oman - Sultan Qabus ibn Sa'id

Saudi Arabia - King Abdullah

Swaziland - King Mswati III

Constitional:

Bahrain - King Hamad bin Isa al-Khalifa

Belgium - King Albert II

Brunei - Sultan Haji Hassanal Bolkiah

Cambodia - King Norodom Sihamoni

Denmark - Queen Margrethe II

Japan - Emperor Akihito

Jordan - King Abdullah II

Kuwait - Sheikh Saad Al Abdullah Al Salim Al Sabah

Lesotho - King Letsie III

Liechtenstein - Prince Hans Adam II

Luxembourg - Grand Duke Henri

Malaysia - King Syed Sirajuddin

Monaco - Prince Albert II

Morocco - King Muhammad VI

Netherlands - Queen Beatrix

Norway - King Harald V

Qatar - Emir Sheik Hamad ibn Khalifa al-Thani

Samoa - Malietoa Tanumafili II

Spain - King Juan Carlos I

Sweden - King Carl XVI Gustaf

Thailand - King Bhumibol Adulyadej

Tonga - King George Tupou V

United Kingdom - Queen Elizabeth II 1