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. In 1627, the Royal Scots Navy and accompanying contingents of burgh privateers participated in the major expedition to Biscay. The Scots also returned to West Indies and in 1629 took part in the capture of Quebec. 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. 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". 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. 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. Royal Navy patrols were now found in Scottish waters even in peacetime. 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. In the 1690s a small fleet of five ships was established by merchants for the Darien Scheme, 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. Scottish armies Before the Wars of the Three Kingdoms in 1644, there was no standing army in the Kingdom of Scotland. In the Early Middle Ages war in Scotland was characterised by the use of small war-bands of household troops often engaging in raids and low level warfare. By the High Middle Ages, the kings of Scotland could command forces of tens of thousands of men for short periods as part of the "common army", mainly of poorly armoured spear and bowmen. After the "Davidian Revolution" of the 12th century, which introduced elements of feudalism to Scotland,