Early tomorrow morning NZ time (10 September) Queen Elizabeth will overtake her great great grandmother Victoria as the longest-serving British monarch.  Each year her Christmas message reveals that the queen is a woman of strong Christian faith. In her 21st birthday message (video at this link) she made a solemn dedication:

I declare before you all that my whole life whether it be long or short shall be devoted to your service and the service of our great imperial family to which we all belong.

But I shall not have strength to carry out this resolution alone unless you join in it with me, as I now invite you to do: I know that your support will be unfailingly given. God help me to make good my vow, and God bless all of you who are willing to share in it.  (full text)

Princess Elizabeth (b.1926) was not born to be queen. In fact there was no imagined chance that she would end up on the throne since at the time of her birth her reigning grandfather (George V) would be succeeded by her uncle who became Edward VIII in January 1936  and was reasonably expected to be succeeded by his children who would have been (if he had children) the first cousins of Elizabeth. The December 1936 abdication of Edward VIII plunged Elizabeth into the immediate line of succession when her father became King George VI. (ref. The King’s Speech)

As we prayed regularly before every movie at a NZ cinema before the early 1970’s “send her victorious, happy and glorious, long to reign over us, God save our Queen.”