List of currently enthroned monarchs and lifelong leaders sorted by length of service:

Current
Time served is in years as of 2007-05-12, rounded down. Note that this is not a list of the longest-serving heads of state; for example, Emir Saqr bin Mohammad al-Qassimi is not head of a sovereign country. His Holiness Tenzin Gyatso, 14th Dalai Lama, has been the enthroned ruler of the exiled Tibetan government for 56 years. His status as a true monarch remains controversial.