However, men were drafted to recruit the 16,000 Hanoverian soldiers fighting in the Low Countries under British command against France. In 1795 the Holy Roman Empire declared its neutrality, including Hanover; however, a peace treaty with France was under negotiation until it failed in 1799. Brandenburg-Prussia, however, ended for its part the war with France by the Treaty of Basel (1795), stipulating that Brandenburg-Prussia would ensure the Holy Roman Empire's neutrality in all the latter's territories north of the demarcation line of the river Main, including the British continental dominions of Hanover, Bremen-Verden, and Saxe-Lauenburg. To this end Hanover also had to provide troops for the so-called demarcation army maintaining the armed neutrality. During the War of the Second Coalition against France (1799–1802) Napoléon Bonaparte urged Brandenburg-Prussia to occupy the continental British dominions. In 1801 24,000 Brandenburg-Prussian soldiers invaded, surprising Hanover, which surrendered without a fight. In April 1801 the Brandenburg-Prussian troops arrived in Bremen-Verden's capital, Stade, and stayed there until October that year. The British first ignored Brandenburg-Prussia's hostility, but when the latter joined the pro-French coalition of armed neutral powers including Denmark-Norway and Russia, Britain began to capture Brandenburg-Prussian ships. After the Battle of Copenhagen (1801) the coalition fell apart and Brandenburg-Prussia withdrew its troops. As part of the German Mediatisation of 25 February 1803, the Electorate received the Prince-Bishopric of Osnabrück in real union, whose every second ruler had been alternately members of the House of Hanover since 1662. After Britain – this time without any allies – had declared war on France (18 May 1803), French troops invaded Hanover on 26 May. According to the Convention of Artlenburg (5 July 1803), confirming the military defeat of Hanover, the Hanoverian army was disarmed and its horses and ammunitions were handed over to the French. The Privy Council of Hanover, with minister Friedrich Franz Dieterich von Bremer holding up the Hanoverian stake, fled to Saxe-Lauenburg across the Elbe, ruled by Britain-Hanover in personal union. Soon afterwards the French also occupied Saxe-Lauenburg.