James I of England and VI of Scotland)
The move from regal union in 1603 to parliamentary union in 1707 and 1800 was far from seamless.
The English parliament rejected political incorporation with Scotland in 1607 and 1670. Irish overtures for incorporation were likewise rejected in 1703, 1707 and 1709.
A proposal for union initiated in the House of Lords in 1695 never got off the ground and another in 1700 was rejected in the House of Commons.
For their part, the Scottish estates favoured 'federative' rather than 'incorporating' union in 1641 and in 1643. A federative union was an association of executive powers that did not involve the subordination or incorporation of the Scottish estates or the English parliament.
The estates had violently split over an incorporating engagement in 1648 and had resisted political union in 1689 and 1702. But the estates, like the Irish parliament, were forced by Oliver Cromwell into an unwanted union with England from 1652 until the restoration of the Stuart monarchy in 1660.
Scottish moves towards commercial union instigated in 1664 were rebuffed in 1668. A similar English initiative never got off the drawing board in 1674 or in 1685.
The transition from regal to incorporating union was severely disrupted by revolution and civil war in both the 17th and 18th centuries.
Charles I was beheaded in 1649. His grandson, James II was removed in 1688-1689 to make way for William of Orange, who married his daughter Mary. In turn, they were succeeded by another daughter Anne in 1702.
British determination to maintain a Protestant succession led to the accession of the house of Hanover in 1714, a distant cadet line of the Stuarts.
The Jacobites, who remained loyal to the main Stuart line in exile, constituted a real if episodic threat to British state formation, until they were vanquished in 1746.
Scotland: Rogue nation
The most important consideration in the making of the United Kingdom in 1707 was the standpoint of England.
Under William of Orange, England had been consolidated as a global power by the massive build up of the army and the navy to fight the French.
England’s war effort was funded through a national debt, supplied increasingly by taxes on trade rather than land.
The largest component of customs dues was levied on the colonial trade. But this trade faced significant disruption from Scottish commercial networks which circumvented the Navigation Acts contrived to protect English domestic and overseas trade.
English feelings that Scotland was acting as a rogue nation contributed greatly to William’s willingness to sabotage the Darien Venture through which Scotland attempted to establish an entrepôt for the East and West Indies on the Panama Isthmus in the late 1690s.
English desires to control the Scots became more acute after the accession of Queen Anne, particularly as the Scots seemed reluctant to accept an eventual Hanoverian succession.
Financial issues became critical as England embarked upon the War of the Spanish Succession. Because the Jacobites were strongly backed by Louis XIV of France, this engagement could well have turned into a war for the British succession.
Renewal of war further exposed a demographic crisis in England and brought about a major shift in government policy in favour of union.
England had insufficient manpower to fight wars, sustain manufacturing and expand its empire. The Scots were a ready reservoir.
Queen Anne played a proactive role in the making of the United Kingdom, not least because she was outraged by the endeavours of the Scottish estates to impose limitations on the prerogative powers of her eventual successor.
If the price of union and the Hanoverian succession was to be the termination of the Scottish estates, so be it. In turn, leading members of the estates, intent on preserving the royal prerogative, securing the Presbyterian Kirk and attaining greater career opportunities through empire promoted Union.
Act of Union, 1707
The Treaty of Union was not a magnanimous, indeed unprecedented, act of altruism in which England rescued an impoverished Scotland - as it has sometimes been portrayed.
Certainly the Scottish balance of trade appeared far from healthy, with imports hugely exceeding exports.
Scottish government was also hard pressed financially. But several caveats are necessary. The impoverishment of government doesn't necessarily mean the impoverishment of the country.
The adverse balance was calculated on taxed trade, not on trade conducted. The balance took no account of imported goods re-exported or reprocessed as manufactures for domestic consumption.
Above all, the balance took no account of the invisible earnings from the thriving Scottish carrying trade from the Baltic to the Caribbean.
The financial capacity of Scottish commercial networks was powerfully demonstrated in the first four months of 1707, before the union became operative on 1 May.
Scottish networks exploited fiscal loopholes by investing £300,000 in brandies, wines, salt and whalebones (for manufacturing into bodices and stays) which they intended to export to England tax free after 1 May.
Until Anne sidelined the English ministry’s attempts to prescribe this activity on the eve of union, its actual implementation was imperilled by vociferous protests from Scottish politicians and merchants.
The enduring popular belief that Scottish politicians were bought and sold for English gold turns attention away from those Scots who negotiated union. They were not so much corrupt as inept.
Their ineptitude was manifested by their stance on colonial access, reparations for Darien and investment in manufactures. All three were secured conditionally.
The East Indies remained the preserve of English commercial interests. Marginally increased reparations were traded off against drastically scaled down investment from what the English ministry had been prepared to offer in return for political incorporation.
By agreeing that reparations and investment should be met by the raising of taxes to English levels, the Scots were effectively financing their own dividends from union.
The Scottish negotiators also accepted a drastic reduction in their nobility eligible for the House of Lords, their numbers being restricted to 16 elected peers. No less significant, only 45 Scottish MPs were to be returned from the shires and burghs to the Commons.
Scottish representation was less than that of Cornwall. In effect, the English parliament became the British parliament with marginal readjustment to accommodate Scottish interests.
Act of Union, 1800
Disaffection within Scotland towards the Treaty of 1707 was soon enhanced by breaches in both the spirit and letter of the union and by delays in honouring fiscal inducement.
Growing resentment about the running of Scotland led to a concerted effort by Scottish politicians at Westminster to terminate the Treaty, which lost narrowly in the lords by four proxy votes in 1713.
The major beneficiaries of political disaffection were undoubtedly the Jacobites, who mounted two serious challenges to the Union in 1715 and 1745.
With the vanquishing of Jacobitism at Culloden, British national identity was promoted assiduously in Scotland, portrayed as patriotism and prosperity imbued by a common commitment to liberty and Protestantism.
Leading figures of the Scottish Enlightenment viewed themselves as the moral guardians of the British constitution established during the 'Glorious Revolution' of 1688-1689 and consolidated by the Treaty of Union in 1707.
Part of this guardianship was a general reawakening of interest in union, which chimed with rising resentment at the protectionist doctrine which denied Ireland free access to empire.
Simultaneously, surveys of empire contrasted the integral partnership claimed for the Scots with the restricted role of the Irish.
The extent to which there should be full legislative and commercial union between Britain and Ireland moved up the political agenda following the American Revolution, when Irish radicalism and constitutional instability were perceived as threatening to England.
The perceived threat during the 1780s was compounded in the next decade by the French Revolution, when Ireland, like Scotland prior to 1707, was seen as the back door to invasion of England from France.
But it was not until moves commenced in Westminster in support of Catholic emancipation that the Protestant ascendancy in Ireland was convinced that incorporating union was more attractive than power-sharing.
After the United Irishmen had courted an abortive French invasion in 1798, the British state moved from oppressive reprisals to advocating union.
Prominent in this British reaction was Henry Dundas, the dominant Scottish politician. He and his political clients were to the fore, arguing the case for political incorporation both at Westminster and in the country at large, based on the reputed advantages that Scotland had enjoyed since 1707.
The Act of Union that was duly negotiated between Britain and Ireland in 1800 again represented the continuation of the English parliament, but with less marginal adjustments in terms of political representation to accommodate Irish interests.
Whereas the Treaty of Union had secured the Presbyterian Kirk, the distinctively Catholic faith of the Irish was disparaged by the Act of Union.
Catholic emancipation remained a distant prospect, not an immediate commitment. Although fiscal dues were not equalised until the 1820s, union for Ireland, as for Scotland in 1707, led to protracted economic recession.
With industrialisation largely confined to Belfast and Dublin, the Irish lacked the entrepreneurial levers or the commitment to empire which had enabled the Scots to grasp the economic opportunities gradually opened up by political incorporation.
An imperial postscript
For the Scots, incorporation with England did not fundamentally alter their Kirk, their legal system or their local government. Only from the mid-19th century did state intervention became the norm rather than the exception.
Notwithstanding the manifest disparity of wealth and resources with England, incorporation was initially viewed in Scotland as a partnership that had particular force within the British empire. The empire cemented Scottish commitment to political incorporation.
For the Irish, union lasted just over a century. The catastrophe of famine in the 1840s, the haemorrhaging of people through emigration, limited industrialisation, a tendency to side with the exploited rather than the exploiters of empire, and ongoing sectarianism were hardly inducements to stay incorporated with Britain.
British over-reaction to the forlorn putsch known as the Easter Rising of 1916 duly paved the way for civil war and the separation of all but six of the 32 counties from Britain by 1922.
Only Northern Ireland has remained part of the United Kingdom, though its Protestant ascendancy can no longer be sustained by political gerrymandering or even direct rule.
Devolution is no guarantee of political stability. At the same time, devolution cannot be regarded as compensating the Scots for the loss of the British empire in the 20th century.
De-industrialisation, civic rejection of Thatcherism and the decline of the National Health Service have eroded the social as well as the political capital of a British identity.
At the time of writing, the Scottish prime minister in Westminster, Gordon Brown, is determined to restore British greatness. The Scottish first minister in Edinburgh is resolved on independence within the European Community. Three-hundred years on from the Treaty of Union, the political will of the Scottish people cannot be regarded as settled.