I want to know the answer to the following question:
Who confirmed the elevation of the Dukes of Brunswick-Lüneburg in 1708?
All the background I'm provided with is that "Thus the principality was upgraded to the Electorate of Brunswick-Lüneburg, colloquially known as the Electorate of Hanover after Calenberg's capital (see also: House of Hanover).". Is that enough to answer the question?