THE queen celebrated her 90th birthday on April 21st and notched up her 23,451st day on the throne. While other monarchs succumb to the Grim Reaper or the discreet charm of retirement, she remains a firm fixture on the list of the world’s most durable rulers. Only Thailand’s King Bhumibol Adulyadej has been calling shots for longer, and that is because he ascended the throne as a teenager (see chart).
