The last letter of Mary Queen of Scots has gone on display to mark the anniversary of her death.

The 430-year-old letter, handwritten in ink just six hours before she was beheaded, is said to be one of the most powerful documents in Scottish history.

In order to preserve it, the fragile letter is only on display between 10am and 7pm on Wednesday, at the National Library of Scotland in Edinburgh.

Long queues formed the last time the letter went on public display in 2009.

It was written at 2am on Wednesday, February 8, 1587, as 44-year-old Mary prepared to meet her executioner at Fotheringhay Castle in Northamptonshire.

Writing in French to Henri III, king of France and the brother of her first husband, she said: "I am to be executed like a criminal at eight in the morning."

Her "crime" was her loyalty to her Catholic faith which, together with her claim to the English throne, made her a threat to her cousin, Elizabeth I of England.

She also expressed concern for the servants she would leave behind who had loyally served her during her 19-year imprisonment in England.

Towards the end of the letter, she asked King Henri to have "prayers offered to God for a queen who has borne the title Most Christian, and who dies a Catholic, stripped of all her possessions."

Although born in Linlithgow Palace, West Lothian, Mary spent the early part of her life in France and was educated in French.

Dr John Scally, national librarian said: "The life of Mary Queen of Scots has fascinated people of all ages for generations. She is one of Scotland's most famous monarchs.

"The National Library is pleased to provide this opportunity to see the last letter she ever wrote only hours before her execution. This is a rare chance to see a remarkable piece of Scottish history."