The Queen has expressed gratitude to well-wishers at home and overseas for their "touching messages of kindness" as she becomes Britain's longest-reigning monarch.

Speaking in the Scottish Borders, the 89-year-old monarch said the title was "not one to which I have ever aspired".

The Queen will have reigned for 63 years and seven months - calculated at 23,226 days, 16 hours and approximately 30 minutes at about 17:30 BST.

David Cameron said the service she had given was "truly humbling".

Dressed in turquoise with her trusty black handbag at her side, the Queen spoke briefly to the gathered crowds on the day she passes the record set by her great-great-grandmother Queen Victoria.

She said: "Inevitably a long life can pass by many milestones - my own is no exception - but I thank you all and the many others at home and overseas for your touching messages of great kindness."