After the war, he supported the forced merger of the SPD and KPD and subsequently co-chaired the SED in Saxony and, briefly, the powerful Central Party Control Commission (ZPKK).

After attending elementary school from 1885 to 1893, Buchwitz completed an apprenticeship as a metal spinner and iron turner until 1896.

He joined the German Metal Workers' Union in 1896 and became a member of the Social Democratic Party (SPD) in 1898.

[1][2] After the Nazis came to power, Buchwitz, along with other SPD Reichstag deputies, voted against the Enabling Act and subsequently went into exile in Denmark.

[1][2] From there, he organized the escape of German regime opponents to Sweden and wrote for the anti-fascist weekly "Freies Deutschland" published in Brussels.

[2] Only a few days after the German occupation of Denmark in April 1940, he was arrested in Copenhagen and handed over to the Gestapo in July.

His fiercest adversary in this regard in Saxony was Stanislaw Trabalski, whom he called Krawalski ("Krawall" meaning "riot" in German).

Subsequently, from April 1946 to December 1948, he co-chaired the SED state leadership in Saxony in parity with former Communist Wilhelm Koenen.

[1][2] On 29 November 1948, he was elected chairman of the Central Party Control Commission (ZPKK), the supreme disciplinary body of the SED, in parity alongside former Communist Hermann Matern.

[1][2] After his death, several streets, schools and other public facilities in the GDR were named after Buchwitz, including a street in East Berlin, the cultural center in Reichenbach/O.L., a youth hostel in Altenberg and an FDGB vacation home (opened in 1984) in Schellerhau near Altenberg,[6] most of which were renamed after German reunification.