The handwritten note which prompted the massacre at Glencoe is to go on display in Edinburgh.
The 20 line letter, featuring the words "to fall upon the rebels ... and put all to the sword under seventy", will form part of a special Homecoming display at the National Library of Scotland.
The note was sent to Robert Campbell of Glenlyon in 1692 and triggered the murder of 38 members of the MacDonald clan.
It will go on display on Thursday and will remain on show, in low light conditions, until January.
The order for the killings, signed by Major Robert Duncanson, followed a proclamation to Scotland's clan leaders, ordering them to pledge allegiance to William III.
The chiefs were expected to take an oath by the end of 1961, but Alasdair MacDonald of Glencoe missed the deadline. Authorities saw his failing as an opportunity to crush the MacDonalds and set about killing the clan members.
A further 40 women and children are also thought to have died of exposure after their homes were burned in the massacre.
Now, the letter behind the killings is to be the centrepiece of an exhibition of Scotland's cultural "treasures" marking the end of Homecoming 2009.
The display also features a handwritten Robert Burns poem reclaimed from the USA and the Forlani Map, thought to be the first map printed to solely feature Scotland.
