Introduction:
During the tumultuous years following World War I, the Weimar Republic in Germany faced significant challenges from various factions, including the Free Corps and the Spartacists. The Free Corps were paramilitary units composed of former soldiers disillusioned with the peace settlement and the perceived weakness of the Weimar government. While they initially opposed the Weimar Republic, they ultimately aligned with the government to suppress the Spartacist uprising.

1. The Free Corps and their opposition to the Weimar Republic:
- The Free Corps emerged as a result of the demobilization of the German army after World War I.
- Many soldiers who had fought on the frontlines felt betrayed by the government's decision to sign the Treaty of Versailles, which they believed to be a humiliating peace settlement.
- The Weimar Republic was seen as weak and responsible for the perceived betrayal of Germany's interests.

2. The Spartacist Uprising:
- The Spartacists were a radical left-wing group led by Karl Liebknecht and Rosa Luxemburg.
- They aimed to establish a communist regime in Germany through a revolution.
- In January 1919, the Spartacists staged an uprising in Berlin, seeking to seize power and overthrow the Weimar government.

3. Cooperation between the Free Corps and the Weimar Republic:
- The Weimar government, fearing the spread of communist revolution, turned to the Free Corps for help in suppressing the Spartacist uprising.
- The Free Corps, despite their initial opposition to the government, saw the Spartacists as a threat to the stability of Germany.
- The Free Corps had a strong anti-communist ideology and saw the Spartacists as a radical and dangerous force.
- The government promised the Free Corps amnesty for their actions during the uprising, effectively turning a blind eye to their extrajudicial methods.

4. Suppression of the Spartacist Uprising:
- The Free Corps, supported by regular army units, successfully crushed the Spartacist uprising.
- The leaders of the Spartacists, Liebknecht and Luxemburg, were captured and later executed.
- The suppression of the Spartacist uprising solidified the Weimar Republic's control and weakened the radical left-wing opposition.

Conclusion:
Although the Free Corps initially opposed the Weimar Republic, they ultimately collaborated with the government to suppress the Spartacist uprising. The Free Corps saw the Spartacists as a threat to the stability of Germany and shared an anti-communist ideology with the Weimar government. The government's promise of amnesty encouraged the Free Corps to assist in suppressing the uprising. This cooperation between the Free Corps and the Weimar Republic contributed to the stabilization of the government and weakened the radical left-wing opposition.