Thailand: King Bhumibol Adulyadej has reigned for a remarkable 67 years, beating England’s Queen Elizabeth, who has served since 1952. He holds a number of little-used, but still important, constitutional powers, including the ability to veto legislation and pardon criminals. Bhumibol is also an interesting figure on his own merits: The 85-year-old king is an accomplished jazz musician and has patented a waste water aerator.