The unsuccessful proclamation of a pro-German duchy was first made in April 1918, after the Republic of Estonia had already formally declared full independence.

The appointed Regency Council, consisting of four Baltic Germans, three Estonians and three Latvians, functioned until 28 November 1918 without any international recognition except from Germany.

In October 1918, the Chancellor of Germany, Prince Maximilian of Baden, proposed to have the military administration in the Baltic replaced by civilian authority.

[8] In Latvia, the Germans formally handed over authority to the Latvian national government, headed by Kārlis Ulmanis on 7 December 1918.

[5] The Baltische Landeswehr was formed in 1919 largely by the leaders of the local Livonian and Curonian nobility, who had been the proponents of the United Baltic Duchy in 1918.

Upon taking command of the Baltische Landeswehr, Major Alfred Fletcher, with the backing of the local nobility, began dismissing native Latvian elements and replacing them with Baltic Germans and Reichsdeutsche troops.

In his book Vanguard of Nazism: The Free Corps Movement in Postwar Germany, 1918–1923, the author Robert G. L. Waite notes: "By mid-February 1919, Latvians composed less than one-fifth of their own army".

In June 1919, after taking part in the capture of Riga, General von der Goltz ordered his troops to advance not east against the Red Army, as the Allies had been expecting, but north against the Estonians.

However, the Baltische Landeswehr was defeated by the 3rd Estonian Division, led by Ernst Põdder, and North Latvian Brigade at the Battle of Cēsis, 19–23 June 1919.