Clan Armstrong is a Scottish kin-group that does not have a recognised chief and is therefore considered to be an armigerous clan.
The legends and traditions of this powerful Borders family hold that the first of the name was Siward Beorn ('sword warrior'), also known as Siward Digry ('sword strong arm'), who was the last Anglo-Danish Earl of Northumberland and a nephew of King Canute, the Danish king of England who reigned until 1035. The family is said to have been related by marriage both to Duncan, King of Scots and William the Conqueror, Duke of Normandy and King of England. <ref>George Way of Plean and Romilly Squire, Scottish Clan and Family Encyclopedia, 352</ref>
The Armstrong name allegedly has a mythological origin, in that it is said their heroic progenitor- Fairbairn- saves the king of Scotland in battle. It is said that, dressed in full armour, he lifted the king onto his own horse with one arm after the King's horse had been killed under him in battle. The family crest records this act of heroism that was to be rewarded with a grant of lands in the Borders and the famous Armstrong name. <ref>http://www.scotclans.com/scottish_clans/clans/armstrong/history.html</ref>
The Armstrongs became a powerful and warlike border clan in Liddisdale and the debateable border land. <ref>Plean, Squire, Encyclopedia, 353</ref> Black lists Adam Armstrong as being pardoned at Carlisle in 1235 for causing the death of another man and Gilbert Armstrong, steward of the household of David II as ambassador to England in 1363. <ref>Plean, Squire, Encyclopedia, 353</ref> The first specific reference locating them in Liddesdale, which would become their family seat, is in 1376. <ref>http://www.scotclans.com/scottish_clans/clans/armstrong/history.html</ref>
Liddesdale was also the seat of their unquestioned power in the region that allowed them to expand into Annandale and Eskdale to accommodate their growing population. It is reputed that by 1528 they were able to put 3000 horsemen in the field. <ref>http://www.scotclans.com/scottish_clans/clans/armstrong/history.html</ref>
The Armstrongs continued to expand their influence into the valleys of the Esk and Ewes, and in about 1425 John, brother of Armstrong of Mangerton, in Liddisdale, built a strong tower at Gilnockie.<ref>Plean, Squire, Encyclopedia, 353</ref>
Gilnockie Tower, Dumfries and Galloway
In 1528 the English warden of the marches, Lord Dacre, attacked and raised the Armstrong tower but the Armstrong response was to burn Netherby. <ref>Plean, Squire, Encyclopedia, 353</ref>
Conflicts with Crown and Diaspora
King James V saw the Armstrongs as a threat to his authority. According to tradition, the king tricked John of Gilnockie to a meeting near Hawick, where the king hanged the laird without further ado. The historian Pitscottie attributes to Armstrong the brave retort that 'King Harry would downweigh my best horse with gold to know I were condemned to die this day'. King James was to rue his treatment of the Armstrongs when they failed to support him at the Battle of Solway Moss in 1542. <ref>Plean, Squire, Encyclopedia, 353</ref>
In 1587 an act was passed by the Scottish parliament "for the quieting and keeping in obedience of the inhabitants of the Borders, Highland and Isles ..." That contained a roll of Chieftains and Clans that confirms the status of Border families as an important part of Clan history, and the Armstrongs as perhaps the most significant Border Clan. The entry began, "On the border were the Armstrongs, brave men, somewhat unruly, and ill to tame ...'
On 16 June 1600, members of the clan ambushed and murdered Sir John Carmichael, warden of the Scottish West march on his way to a warden court at Langholm. The union of the Crowns in 1603 brought an official end to the Anglo-Scottish border wars and the last of the Armstrong lairds was hanged in Edinburgh in 1610 for leading a reiving raid on Penrith. <ref>Plean, Squire, Encyclopedia, 353</ref>A ruthless campaign followed as the Crown attempted to pacify the Borders. <ref>Plean, Squire, Encyclopedia, 353</ref>
The families were scattered and many sought new homes in Ulster, particularly in Fermanagh. Armstrong is now among the fifty most common Ulster surnames.<ref>Plean, Squire, Encyclopedia, 353</ref>
A descendant, Neil Armstrong, became the first man to walk on the moon in 1969.<ref>Plean, Squire, Encyclopedia, 353</ref> There has been no trace of the Armstrong chiefs since the seventeenth century, but there is an active clan association who curate Gilnockie Tower, which houses a clan museum. It was restored in 1978 by Major T.C.R Armstrong Wilson. <ref>http://en.wikipedia.org/wiki/Gilnockie_Tower</ref>
Clan Armstrong are represented on the Council of Scottish Armigerous Clans and Families by Micheil J. Armstrong of Mungbyhurst KLJ, FCI, FSA Scot. <ref>http://www.clans-families.org/council--members.html</ref>