Historically, Scotland has a long military tradition that predates the Act of Union with England in 1707. Its soldiers today form part of the armed forces of the United Kingdom, more usually referred to domestically within the UK as the British Armed Forces.

History prior to the Union

Royal Scots Navy

There are mentions in Medieval records of fleets commanded by Scottish kings including William the LionP. F. Tytler, History of Scotland, Volume 2 (London: Black, 1829), pp. 309–10. and Alexander II. The latter took personal command of a large naval force which sailed from the Firth of Clyde and anchored off the island of Kerrera in 1249, intended to transport his army in a campaign against the Kingdom of the Isles, but he died before the campaign could begin.J. Hunter, Last of the Free: A History of the Highlands and Islands of Scotland (London: Random House, 2011), , pp. 106–111.A. Macquarrie, Medieval Scotland: Kinship and Nation (Thrupp: Sutton, 2004), , p. 147. Viking naval power was disrupted by conflicts between the Scandinavian kingdoms, but entered a period of resurgence in the thirteenth century when Norwegian kings began to build some of the largest ships seen in Northern European waters. These included king Hakon Hakonsson's Kristsúðin, built at Bergen from 1262 to 1263, which was long, of 37 rooms.N. A. M. Rodger, The Safeguard of the Sea: A Naval History of Britain 660–1649 (London: Penguin UK, 2004), , pp. 74–5. In 1263 Hakon responded to Alexander III's designs on the Hebrides by personally leading a major fleet of forty vessels, including the Kristsúðin, to the islands, where they were swelled by local allies to as many as 200 ships.P. J. Potter, Gothic Kings of Britain: the Lives of 31 Medieval Rulers, 1016–1399 (Jefferson, North Carolina: McFarland, 2008), , p. 157. Records indicate that Alexander had several large oared ships built at Ayr, but he avoided a sea battle. Defeat on land at the Battle of Largs and winter storms forced the Norwegian fleet to return home, leaving the Scottish crown as the major power in the region and leading to the ceding of the Western Isles to Alexander in 1266.A. Macquarrie, Medieval Scotland: Kinship and Nation (Thrupp: Sutton, 2004), , p. 153.

English naval power was vital to Edward I's successful campaigns in Scotland from 1296, using largely merchant ships from England, Ireland and his allies in the Islands to transport and supply his armies.N. A. M. Rodger, The Safeguard of the Sea: A Naval History of Britain. Volume One 660–1649 (London: Harper, 1997) pp. 74–90. Part of the reason for Robert I's success was his ability to call on naval forces from the Islands. As a result of the expulsion of the Flemings from England in 1303, he gained the support of a major naval power in the North Sea. The development of naval power allowed Robert to successfully defeat English attempts to capture him in the Highlands and Islands and to blockade major English controlled fortresses at Perth and Stirling, the last forcing Edward II to attempt the relief that resulted at English defeat at Bannockburn in 1314. Scottish naval forces allowed invasions of the Isle of Man in 1313 and 1317 and Ireland in 1315. They were also crucial in the blockade of Berwick, which led to its fall in 1318.

After the establishment of Scottish independence, Robert I turned his attention to building up a Scottish naval capacity. This was largely focused on the west coast, with the Exchequer Rolls of 1326 recording the feudal duties of his vassals in that region to aid him with their vessels and crews. Towards the end of his reign he supervised the building of at least one royal man-of-war near his palace at Cardross on the River Clyde. In the late fourteenth century naval warfare with England was conducted largely by hired Scots, Flemish and French merchantmen and privateers.J. Grant, "The Old Scots Navy from 1689 to 1710", Publications of the Navy Records Society, 44 (London: Navy Records Society, 1913-4), pp. i–xii. James I took a greater interest in naval power. After his return to Scotland in 1424, he established a shipbuilding yard at Leith, a house for marine stores, and a workshop. King's ships were built and equipped there to be used for trade as well as war, one of which accompanied him on his expedition to the Islands in 1429. The office of Lord High Admiral was probably founded in this period. In his struggles with his nobles in 1488 James III received assistance from his two warships the Flower and the King's Carvel also known as the Yellow Carvel.

There were various attempts to create royal naval forces in the fifteenth century. James IV put the enterprise on a new footing, founding a harbour at Newhaven and a dockyard at the Pools of Airth.N. Macdougall, James IV (Tuckwell, 1997), p. 235. He acquired a total of 38 ships including the Great Michael,T. Christopher Smout, Scotland and the Sea (Edinburgh: Rowman and Littlefield, 1992), , p. 45. at that time, the largest ship in Europe.S. Murdoch, The Terror of the Seas?: Scottish Maritime Warfare, 1513–1713 (Leiden: Brill, 2010), , pp. 33–4. Scottish ships had some success against privateers, accompanied the king on his expeditions in the islands and intervened in conflicts Scandinavia and the Baltic, but were sold after the Flodden campaign and after 1516 and Scottish naval efforts would rely on privateering captains and hired merchantmen. James V did not share his father's interest in developing a navy and shipbuilding fell behind the Low Countries.J. E. A. Dawson, Scotland Re-Formed, 1488–1587 (Edinburgh: Edinburgh University Press, 2007), , pp. 181–2. Despite truces between England and Scotland there were periodic outbreaks of a guerre de course.S. Murdoch, The Terror of the Seas?: Scottish Maritime Warfare 1513–1713 (Leiden: Brill, 2010), , p. 39. James V built a new harbour at Burntisland in 1542.T. Andrea, The Princelie Majestie: The Court of James V of Scotland 1528–1542 (Birlinn, 2005), p. 164. The chief use of naval power in his reign was a series of expeditions to the Isles and France.J. E. A. Dawson, Scotland Re-Formed, 1488–1587 (Edinburgh: Edinburgh University Press, 2007), , p. 76. After the Union of Crowns in 1603 conflict between Scotland and England ended, but Scotland found itself involved in England's foreign policy, opening up Scottish shipping to attack. In 1626 a squadron of three ships were bought and equipped. There were also several marque fleets of privateers.S. Murdoch, The Terror of the Seas?: Scottish Maritime Warfare, 1513–1713 (Leiden: Brill, 2010), , p. 169. In 1627, the Royal Scots Navy and accompanying contingents of burgh privateers participated in the major expedition to Biscay.R. B. Manning, An Apprenticeship in Arms: The Origins of the British Army 1585–1702 (Oxford: Oxford University Press, 2006), , p. 118. The Scots also returned to West IndiesS. Murdoch, The Terror of the Seas?: Scottish Maritime Warfare, 1513–1713 (Leiden: Brill, 2010), , p. 172. and in 1629 took part in the capture of Quebec.S. Murdoch, The Terror of the Seas?: Scottish Maritime Warfare, 1513–1713 (Leiden: Brill, 2010), , p. 174.

During the Bishop's Wars the king attempted to blockade Scotland and planned amphibious assaults from England on the East coast and from Ireland to the West. Scottish privateers took a number of English prizes.S. Murdoch, The Terror of the Seas?: Scottish Maritime Warfare, 1513–1713 (Leiden: Brill, 2010), , p. 198. After the Covenanters allied with the English Parliament they established two patrol squadrons for the Atlantic and North Sea coasts, known collectively as the "Scotch Guard".S. Murdoch, The Terror of the Seas?: Scottish Maritime Warfare, 1513–1713 (Leiden: Brill, 2010), , pp. 204–10. The Scottish navy was unable to withstand the English fleet that accompanied the army led by Cromwell that conquered Scotland in 1649–51 and the Scottish ships and crews were split up among the Commonwealth fleet.S. Murdoch, The Terror of the Seas?: Scottish Maritime Warfare 1513–1713 (Leiden: Brill, 2010), , p. 239. Scottish seamen received protection against arbitrary impressment by English men of war, but a fixed quota of conscripts for the Royal Navy was levied from the sea-coast burghs during the second half of the seventeenth century.D. Brunsman, The Evil Necessity: British Naval Impressment in the Eighteenth-Century Atlantic World (University of Virginia Press, 2013), . Royal Navy patrols were now found in Scottish waters even in peacetime.A.Campbell, A History of Clan Campbell: From The Restoration To The Present Day (Edinburgh: Edinburgh University Press, 2004), , p. 44. In the Second (1665–67) and Third Anglo-Dutch Wars (1672–74) between 80 and 120 captains, took Scottish letters of marque and privateers played a major part in the naval conflict.S. Murdoch, The Terror of the Seas?: Scottish Maritime Warfare 1513–1713 (Leiden: Brill, 2010), , pp. 239–41. In the 1690s a small fleet of five ships was established by merchants for the Darien Scheme,A. I. MacInnes and A. H. Williamson, eds., Shaping the Stuart World, 1603–1714: The Atlantic Connection (Brill, 2006), , p. 349. and a professional navy was established for the protection of commerce in home waters during the Nine Years' War, with three purpose-built warships bought from English shipbuilders in 1696. After the Act of Union in 1707, these vessels were transferred to the Royal Navy.J. Grant, "The Old Scots Navy from 1689 to 1710", Publications of the Navy Records Society, 44 (London: Navy Records Society, 1913-4), p. 48.

Scottish armies