jurisdiction, Bremen-Verden's Estates maintained their stake. But Bremen-Verden's tax-levying department, almost entirely manned with Swedes and using Swedish as administrative language, was directly subordinated to the finance ministry in Stockholm. From 1675 to 1676, troops from Brandenburg-Prussia, Lüneburg-Celle, Denmark-Norway, and the Prince-Bishopric of Münster captured Bremen-Verden in the course of a Reichsexekution during the Scanian War. The allied forces occupied Bremen-Verden, until they withdrew — under French influence — according to the Treaty of Saint-Germain-en-Laye of 1679 and the favourable Treaty of Celle. By the latter Baron , the Prince-Bishop of Münster, granted Sweden a loan amounting to 100,000 rixdollars, for which in return Swedish Bremen-Verden had to pawn its exclave of the town of Wildeshausen and the pertaining adjacence to the Prince-Bishopric of Münster. In the 1690s, the usual practise, that tax laws had a certain maturity, was abolished, so that the Swedish and Bremen-Verden's Estates had no chance any more to demand any concessions in return for a renewal of tax laws. As in Sweden proper, the constitutional and administrative bodies in the Swedish dominions gradually lost de facto importance due to ever growing centralisation. Bremen-Verden's Estates lost more and more influence, they less and less often convened. After 1692, the estates' say had almost vanished. This led to considerable unease among the Estates, so that in May 1694 representatives of the General Government of Bremen-Verden and the Estates met at the former convent of Zeven to confer on the status of the Duchies. In 1700, Bremen-Verden introduced — like all Protestant territories of imperial immediacy — the Improved Calendar, as it was called by Protestants, in order not to mention the name of Pope Gregory XIII. So Sunday 18 February, Old Style, was followed by Monday 1 March, New Style, while Sweden proper only followed suit in 1753. In 1712, in the course of the Great Northern War (1700–1721) against the Swedish supremacy in the Baltic, Denmark-Norway occupied plague stricken Bremen-Verden. Personal union with Great Britain and Hanover (1715–1803) In 1715, Frederick IV of Denmark, still fighting in the Great Northern War, gained a new ally in the anti-Swedish coalition, George I, King of Great Britain since 1714, and Elector of Hanover. In return for George I's aid, Denmark-Norway sold to him Bremen-Verden, which it kept under occupation since 1712. So the Prince-Electorate of Brunswick and Lunenburg, or colloquially called after its capital, the Electorate of Hanover;