(I wrote this piece before realising that Christina Victor's blogpost had already been posted. Oh well, we can have two about Queen Elizabeth since it's not everyday that a British monarch turns 90. In fact, it's the only day ever that a British monarch has turned 90. The next closest to her in age were Victoria and George III who both died at 81. George II made it to 76. Edward VIII was 78 when he died, but of course he wasn't reigning at the time and so we will forget about him...)
Late last week Her Majesty the Queen turned 90. For those of you unlucky enough not to have been part of the Empire on which the sun never sets, or for those of you whose forebears were ungrateful enough to rebel from said Empire, I'm talking about Queen Elizabeth II, the reigning monarch of the United Kingdom and other Commonwealth realms (including New Zealand). Born on 21 April 1926 (although we don't officially celebrate her birthday here in New Zealand until 6 June!) her Majesty has certainly lived through an awful amount of change and trials. The Depression, World War II, the Iron Curtain and the Cold War, the loss of an Empire, the diminution of the United Kingdom from the first tier of powers to the middle of the second tier, the Suez Crisis, the Malayan Emergency, the Falklands War, a couple of Gulf Wars, the fall of the USSR and New Zealand winning the Rugby World Cup Three times have all occurred during her lifetime. 
The Telegraph has a rather interesting piece comparing the British population in 1926 to now. When her Majesty was born, the chances of a baby girl reaching 90 years of age was 4.2% (in fact, around 100,000 women born that year have managed this feat alongside Elizabeth). The average life expectancy of a girl born in 1926 was 70.6 years. Nowadays, a girl born has an average life expectancy of nearly 94 years (!) and has a one-in-three chance of reaching 90 years. While her Majesty is in a select 90 year old cohort, in the future it will be old-hat. The increase in life expectancy has been just as dramatic for males - rising from 64.1 years in 1926 to nearly 91 years today.