England hasn’t “always been keen” to incorporate Scotland. It’s been touch-and-go over the centuries. While economic and political questions were at stake, the early steps toward unification were driven by religious considerations.

England was in an unfriendly neighborhood in Europe in the early sixteenth century. Its most immediate neighbors France and Scotland had been under the “Auld Alliance” since the late thirteenth century. The alliance promised retaliatory action if one partner were invaded by England, and it had been invoked several times, including in 1513. After Henry VIII's break from the church in Rome, the geopolitical tensions were compounded by new religious pressures as England found itself surrounded by Catholic neighbors. After Henry’s failed attempts to pressure James V of Scotland to reject the Roman Church, England sent troops to raid Scotland. The Scots responded, resulting in their humiliating retreat at the Battle of Solway Moss. James V died shortly after receiving the news, leaving as his only heir a baby daughter named Mary.

Henry VIII saw an opportunity in this situation to form a dynastic union and put an end to the pattern of warfare. He had a young son (later to be crowned Edward VI), who he hoped to marry to the infant queen of Scotland. However the Scottish regent, the Earl of Arran, refused to quit the alliance with France. Henry’s militaristic response to the failed proposal is known as the Rough Wooing. With the Scottish parliament’s refusal of his proposal, Henry sent punitive expeditions to Scotland, attacking and setting fire to Edinburgh and burning other towns along the way. Queen Mary was during this time betrothed to the French Dauphin.

A union of the crowns would occur in another half century. During this time, much of Scotland, including King James VI, had become Protestant. As Elizabeth I of England approached her death unmarried and childless, one of her ministers prepared for the succession of her closest Protestant kin, James VI (related by the 1503 marriage of the daughter of Henry VII’s daughter Margaret Tudor to James IV of Scotland). In 1603 after Elizabeth’s death, James VI became James I of England, in what is referred to as the Union of the Crowns.

Composite monarchies such as this were common in early modern Europe. The obvious choice for James VI & I was to rule from England, the larger and more wealthy of his two kingdoms. He paraded through the country, which was put on alert for violence, but the people of England received him well with festivals and ceremony. On arriving in the English parliament, he endeavored to enact a complete union between the two kingdoms to create a combined British state, but English parliamentarians largely opposed it. During the seventeenth-century, James and others who talked of union imagined it as a religious project to unite the Protestant kingdoms.

The true union occurred in 1707. Negotiations had been reopened for several reasons, predominantly dynastic and economic. Queen Anne, despite many pregnancies, had no surviving children. The Act of Settlement of 1701 had secured the succession of George, the Elector of Hanover, though there was a concern that Scotland would not accept the same succession as England. For their part, the Scots looked to a union to recover from the disastrous Darien scheme. The scheme had sought to establish a colony of Caledonia in Panama, but failed miserably because of epidemics, poor provisioning, and Spanish attack. Many investors were ruined by the scheme. As part of the union, England stabilized the Scottish currency and granted Scotland a lump sum of money to offset their taking on payments toward the English national debt. Entering into the union would also give Scots what they had sought from the scheme to begin with: colonial interests and broader markets. Moreover, in the coming years, aspiring Scots would benefit from the positions opened to them in the British Empire, becoming prominent army officers, slave traders, and colonial governors. Many English people felt the partnership to be unequal, given that England was the wealthier partner. Even decades after the union, the English public expressed strong Scottophobia, in part because of the perception that Scots were taking advantage of English positions at home and abroad.