The Vienna Congress of 1815 decisively renewed the affiliation of the Grafschaft with the King of Hanover. With the definitive expulsion of the French from the Grafschaf in 1813 by Russian troops following the Battle of Leipzig, count Alexis of Bentheim and Steinfurt was able to take possession of the country in his father's name for a few days, but had to yield to the Hanoverians. The Royal Britannic Hannoverian administration of Bentheim county was set up in Bentheim. The omission of references to the pledge characterized the objective of Hannoverian politics, with the intent to annex the Grafschaft permanently. In fact, the laws and regulations passed during the French Occupation were generally repealed, the legal authorities retained and also the city and local community administration related regulations remained in force, in doing so the concept of the mayor was replaced by Bürgermeister.

In 1815, the Vienna Congress arranged anew the territorial circumstances in all of Europe at the expense of many small states; its final act bestowed (which was elevated to a kingdom in 1814) to Hannover considerable territorial gains, it confirmed at the same time the Hannovarian pledge rights over the Bentheim Grafschaft and dictated that through its redemption the Grafschaft should be brought under the control of the Kingdom of Hannover.

In terminating the pledge contract of 1752 the discernably far sighted Hannoverian policy had the hoped for success; Prussia was eliminated as a competitor in the border region with the Netherlands, that is, Rheina-Wolbeck and Meppen, and surrendered East Frisia. An all around territorial stranglehold of Hannover by Prussia, which was completely within their means, was thereby avoided.

Against the provisions of the pledge contract, whose validity particularly regarding territorial sovereignty the Congress act of 1815 had explicitly acknowledged, Hannover began at once with the objective to virtually integrate the Bentheim territory into the prevailing system in the rest of the Hannoverian territories with concrete and massive inroads in its law and administration.

In 1816 the Hannovarian Military and Postal Administration, and in 1817 the general Taxation system were established. In 1818 even the general royal estates assembly was made responsible for Bentheim.

Hannover was completely aware of the questionable legality of its behavior, it was only possible for the Ministry to report in 1821 that apart from the pledge contract, Hannover had not yet obtained Sovereignty over Bentheim.

After years of tough negotiations between the two very unequal contractual partners, the king and the count (he was elevated to the rank of Prince by the Prussians; Hannover recognized the elevation) who due to widely divergent prospects about options and details of a compromise over the mutual financial claims and sovereign authority led to no conclusion, the king, in contempt of recognized legal principles, terminated the pledge on September 1, 1822 and discontinued the payments to the prince. Following these measures the prince was forced in 1823 to approve an arrangement over the annulment of the pledge, in which against the aim fixed in the Congress act he was exempted from only a portion of the pledge amount; it restored his domain to him and compensated him for the renunciation of effective sovereignty, ceded to him notably the goods of the disbanded Wietmarschen Cloister and also partially of the Frenswegens disbanded cloister.