A question that I am often asked is 'How Did Scotland Become Part of Great Britain and the United Kingdom ?'..... well its a long story, but fairly straight forward.
The borderland between what is now Scotland and England had always been troublesome, since before the Roman conquest. Raiders from Scotland used to rampage South looking for plunder and livestock, as did raiders from South of the Border. As Europe settled into a system of feudalism, great Lords, including the Kings of Scotland and England laid claim to these areas. There were still constant disputes, with Kings in England and Scotland trying to invade and subdue each other.
However, In 1603, James VI King of Scots inherited the throne of the Kingdom of England, and became King James I of England, leaving Edinburgh for London, uniting England and Scotland under one monarch. England was now ruled by a Scot. The Union was a personal or dynastic union, with the Crowns remaining both distinct and separate—despite James's best efforts to create a new "imperial" throne of "Great Britain". The acquisition of the Irish crowncottish King, along with the English, facilitated a process of settlement by Scots in what was historically the most troublesome area of the kingdom in Ulster, with perhaps 50,000 Scots settling in the province by the mid-17th century. Attempts to found a Scottish colony in North America in Nova Scotia were largely unsuccessful, with insufficient funds and willing colonists
The closing decade of the 17th century saw the generally favourable economic conditions that had dominated since the Restoration come to an end. There was a slump in trade with the Baltic and France from 1689–91, caused by French protectionism and changes in the Scottish cattle trade, followed by four years of failed harvests (1695, 1696 and 1698-9), an era known as the "seven ill years". The result was severe famine and depopulation, particularly in the north.The Parliament of Scotland of 1695 enacted proposals that might help the desperate economic situation, including setting up the Bank of Scotland. The "Company of Scotland Trading to Africa and the Indies" received a charter to raise capital through public subscription.
With the dream of building a lucrative overseas colony for Scotland, the Company of Scotland invested in the Darien scheme, an ambitious plan devised by William Paterson to establish a colony on the Isthmus of Panama in the hope of establishing trade with the Far East. The Darién scheme won widespread support in Scotland as the landed gentry and the merchant class were in agreement in seeing overseas trade and colonialism as routes to upgrade Scotland's economy. Since the capital resources of the Edinburgh merchants and landholder elite were insufficient, the company appealed to middling social ranks, who responded with patriotic fervour to the call for money; the lower classes volunteered as colonists. But the English government opposed the idea: involved in the War of the Grand Alliance from 1689 to 1697 against France, it did not want to offend Spain, which claimed the territory as part of New Granada. The English investors withdrew. Returning to Edinburgh, the Company raised 400,000 pounds in a few weeks. Three small fleets with a total of 3,000 men eventually set out for Panama in 1698. The exercise proved a disaster. Poorly equipped; beset by incessant rain; under attack by the Spanish from nearby Cartagena; and refused aid by the English in the West Indies, the colonists abandoned their project in 1700. Only 1,000 survived and only one ship managed to return to Scotland. As a result, Scotland, who had invested a huge proportion of its national income in the venture, was financially broken.
Scotland's transformation into a rich leader of modern industry came suddenly and unexpectedly in the next 150 years, following its union with England in 1707 and its integration with the advanced English and imperial economies. The transformation was led by two cities that grew rapidly after 1770. Glasgow, on the river Clyde, was the base for the tobacco and sugar trade with an emerging textile industry. Edinburgh was the administrative and intellectual centre where the Scottish Enlightenment was chiefly based
Although Scotland lost home rule, Union allowed it to break free of a stultifying system and opened the way for the Scottish enlightenment as well as a great expansion of trade and increase in opportunity and wealth. Edinburgh economist Adam Smith concluded in 1776 that "By the union with England, the middling and inferior ranks of people in Scotland gained a complete deliverance from the power of an aristocracy which had always before oppressed them." Historian Jonathan Israel holds that the Union "proved a decisive catalyst politically and economically," by allowing ambitious Scots entry on an equal basis to a rich expanding empire and its increasing trade.
By the start of the 18th century, a political union between Scotland and England became politically and economically attractive, promising to open up the much larger markets of England, as well as those of the growing British Empire. With economic stagnation since the late 17th century, which was particularly acute in 1704; the country depended more and more heavily on sales of cattle and linen to England, who used this to create pressure for a union. The Scottish parliament voted on 6 January 1707, by 110 to 69, to adopt the Treaty of Union. It was also a full economic union; indeed, most of its 25 articles dealt with economic arrangements for the new state known as "Great Britain". It added 45 Scots to the 513 members of the House of Commons and 16 Scots to the 190 members of the House of Lords, and ended the Scottish parliament. It also replaced the Scottish systems of currency, taxation and laws regulating trade with laws made in London. Scottish law remained separate from English law, and the religious system was not changed. England had about five times the population of Scotland at the time, and about 36 times as much wealth.
Jacobitism, was a result of people being unhappy with the Union...... but that's another story :-)
So, in answer to all the questions about Scottish independence...... Scotland was never invaded, and voluntarily joined with England and Wales and Ireland (at the time).... an opportunity created by a Scottish lineage ruling in London.