Her majesty is already by nearly a decade the longest lived reigning British monarch. Her two predecessors as holders both of that distinction and of that for longest reign, Queen Victoria and King George III, both died at the age of 81 and the present Queen celebrated her 90th birthday this year.
My son asked me the question on the day that Queen Elizabeth's reign became one year longer than that of her great, great Grandmother, Queen Victoria.
(For any Jacobites reading this blog, in May Queen Elizabeth's reign exceeded the length of the claimed reign of Prince James Francis Edward Stuart (known to non-traitors as the "Old Pretender.")
If (d.v.) she should live to reach the dates of
I know that Her majesty did not want too much fuss made of the point when the length of her reign passed that of Queen Victoria - as it was a distinction that she earned mainly by living for a long time - but given the above points it will be a remarkable thing if she does live to the age of 100 and certainly worthy of celebration.
I would have thought the appropriate answer to my son's question is that the office which sends all other centenarians a telegram on behalf of the Queen should send one to her on behalf of the Prime Minister.