The Reichsdeputationshauptschluss conclusion was a resolution of the last meeting of the Immerwaehrenden realm tags on 25 February 1803 in Regensburg. It in June 1802 a remuneration plan agreed upon between France and Russia was the basis, which is based on the peace treaty of Lunéville. The main conclusion is the last large law of the holy Roman realm of German nation.

The French revolution wars had shifted the French east border up to the Rhine and had brought with it numerous German princes their linksrheinischen possessions. In theReichsdeputationshauptschluss, it was determined that these should be compensated bychurch(secularization) and layrealm conditions(Mediatisierung). In addition the religious principalities (with exception of Mainz, whose territory would transfer connected with that a cure ore chancellor to Regensburg became) and the free realm cities (with exception of Augsburg, Luebeck, Nuernberg, Frankfurt/Main, Bremen and Hamburg) were dissolved and slammed shut the neighbouring large principalities. First also the German medal and the Malteserorden remained excluded from the secularization. The princes at the same time received Cologne ,Trier andPfalz from Salzburg , Wuerttemberg , Baden and Hessen-Kassel the extinct cure principalities.

The Reichsdeputationshauptschluss was ratified in March 1803 unanimously from the realm day; the emperor followed in April - although under reservation - this vote.

The secularization and the following Mediatisierung changed the German Reich completely. The emperor lost his principal supports in the realm with the religious princes and realm cities. So far the catholic dominated realm prince advice became by the majority Evangelist. After also the realm knight shank and many small principalities to 1806 had lost their independence, the number of the territories of some hundreds reduced to approximately thirty-four. Principalities such as a bathing, Bavaria or Wuerttemberg could book thereby large area gains, were in response however obligated to loyalty opposite Napoleon.

Borders and rule areas settled and finally led it to the collapse of the finely counterbalanced rule system of the holy Roman realm of German nation: 1806 put emperors Franz II. crown down.