As the new government struggled to maintain the requirements of Versailles (and avoid many of it's terms), many were still unhappy with the new status quo. While the army had made an agreement with the ruling government, it was still unhappy with the leftist coalition and outraged over the signing of the Treaty of Versailles. Rumors abounded about military groups overthrowing the government, some about the Reichswehr itself and others from paramilitary groups like the various Freikorps. This lead to constant tension between the Weimar government and the military groups that were supposedly supposed to be propping it up. This would come to a head as the Weimar government finally deciding to make a stand, demanding the Marinebrigade Loewenfeld and Marinebrigade Ehrhardt de-arm and disband. They were made up of far-right military leaders and veterans who were publicly supporting calls for the Weimar government to be overthrown. The SPD and USPD ruling parties believed by forcing these elite Freikorps to disband, they would make a public statement against these reactionary groups.

This would seemingly backfire as the general of the Reichswehr in Berlin, Walther von Lüttwitz, invited the two Freikorps groups into Berlin and held a rally. There Walther along with the leaders of the Freikorps openly spoke out against the Weimar government and their issues with the current state of affairs in Germany. After the successful rally, Walther and his associates met and prepared their men. Not all of Walther's officers were prepared to support him however, and some alerted the Weimar government to the coup attempt. President Schiedemann demanded a meeting where he would listen to their complaints in the hopes of creating a compromise. They met in the President's office, and Walther laid out his demands. He demanded another snap election, a reshuffling of the cabinet to include many of the right and far-right parties, the two Freikorps disbandment to be repealed, the USPD to be banned, and for himself to be made as the Supreme Commander of the Reichswehr. Scheidemann outright refused the demands, and threw Walther out of his office. Walther then returned to the leaders of the Marinebrigade Loewenfeld and Marinebrigade Ehrhardt and asked if they would be able to occupy Berlin with the support of whatever units of the Reichswehr that were still loyal to Walther and not the Weimar government. They agreed that after two days time, the Freikorps would be capable. On December 11th, they moved on Berlin and quickly began to occupy the capital. A meeting was arranged between the leadership of the DNVP, the right wing party that made 20% of the Reichstag including Wolfgang Kapp, the old Berlin Chief of Police before the Weimar government removed him from his position, the German Social Party, a German hyper-nationalist party on the far right, and Ludendorff, a retired general. Due to mixed support from the regular officers in the Reichswehr, Walther was convinced to allow the Weimar government to surrender. The Weimar government held an emergency meeting, in which a near-unanimous vote was taken refusing to surrender to the putschists. However, they were split on whether to flee the city or attempt to fight back. As the putschists moved to surround government buildings, the next in line commander Hans von Seeckt was asked to fire on the putschists. He vehemently refused these orders, being quoted as saying "Reichswehr does not fire on Reichswehr!" As the Defense Minister Otto Gessler reported this to the Weimar government, chaos broke out. The putschists were coming closer and closer, and eventually action had to be taken. The entirety of the cabinet fled as well as the vast majority of the USPD and SPD politicians. The more centrist parties like the DDP and DVP did not agree, as most fled the capital awaiting future developments but with some privately supporting the putschists. They announced the dismissal of Walther as general and put out the arrest warrants for all the putschist leaders.

The provisional government of the putschists quickly arose. Kapp announced himself as the new Chancellor, with the DNVP filling all the ministry positions. Walther was announced as the Defence Minister and Supreme Commander of the Reichswehr. The Admiral of the German Navy, Adolf von Trotha, came out in support of the new government. Military commands of Brandenburg and Pomerania as well as Saxony came out in support too. Other military commands were either neutral or privately were in support of the putschists. The Weimar government set up shop in Hamburg, and the SPD-USPD coalition called for a nation-wide strike. Furthermore, in response a new party has announced itself, called the Communist Party of Germany (KPD), its leaders announced as Franz Mehring and Paul Levi. They were made up primarily of pro-Bolshevik communists and had called for a violent uprising primarily within the Ruhr region against the putchists.