In the first decade of the 18th Century two great wars were raging over Europe. The war over the Spanish inheritance was fought in the Spanish-Netherlands, the Rhineland, the Iberian Peninsula and several other regions. In the northern and eastern parts of Europa a conflict was fought, The Great Northern War, with Sweden, Denmark, Russia and Saxony (- Poland) being the main belligerents.
As the Great Northern War was fought in parts of the Holy Roman Empire fear existed that the war might mix with the war over the Spanish succession. The two treaties of Altranstädt of 1706 and 1707 (peace between Sweden and Saxony, and treaty between Sweden and the Emperor) took away the tension for some time. Of interest is to note that in 1707 part of the Saxon army was taken into pay of the Maritime powers.
However, in 1709 the Swedish king Karl XII was defeated by the Russians at Poltava, leading to the former's voluntary exile into Ottoman territory. This created some sort of a void in the Baltic area with Russia, Denmark and Saxony looking with much interest at Swedish territories in the region. The expected return of Karl XII and renewal of the war in the Holy Roman Empire was feared. Moreover, with the war spreading into these Swedish possessions of the Empire it was feared that Brandenburg-Prussia and Hanover might be involved as well. Which would obviously influence their part in the war against France.
On 31 March 1710 the Maritime Powers and the Emperor signed the convention of the Hague. This convention declared for the neutrality of the Swedish possessions in the Empire. In order to enforce this neutrality the signers of the convention, together with several other German powers, agreed to contribute to a corps of Neutrality. The size of the corps was set at 15,400 foot and 3,000 horse. England and the Dutch Republic would contribute six battalions each, in total 8,400 men. Other contributors were the Emperor, Prussia, Hanover, the Palatinate, Mainz, Hessen-Kassel, Münster, Mecklenburg and Wolfenbüttel.
Though the situation remained strained throughout 1710, and several contingents had already marched into Silezia, the Neutrality Corps did not have to come into action. Not because of the corps' deterrent effect, but because the events in the region, and return of the Swedish king, did not proceed as fast as expected.
Hostilities were resumed in 1711 anyway and the Great Northern War would continue until 1721. It also remains to be questioned how effective the corps would have been in case it should have to come into action.