A political opponent of Ernst Thälmann, Meyer was moved out of the top party leadership after 1928, not long before his death of tuberculosis-related pneumonia at the age of 43.

[2] At the time of World War I, Meyer took his place on the extreme left of the SPD, along with Rosa Luxemburg, Karl Liebknecht, Franz Mehring, and Clara Zetkin.

[3] Meyer and his Spartacist comrade, Bertha Thälheimer, did not lend their support to the resolution of the Zimmerwald Left at that gathering demanding an immediate break of revolutionary socialists from the reformist wing of the Social Democratic movement.

[4] During the German Revolution of 1918–19, Meyer emerged to serve on the editorial board of Die Rote Fahne (The Red Flag), the official organ of the Communist Party.

[1] Meyer reported on the agrarian question to the 2nd Congress, which elected him to the Executive Committee of the Communist International (ECCI) and its Presidium.

[1] At the August 1921 congress of the KPD, Meyer delivered the keynote speech, the political report of the Zentrale, emphasizing his place as a top leader of the organization.

[6] Meyer again delivered the key political report to the KPD's January 1923 party congress, but this time he was not re-elected to the Central Committee.

[2] In the spring of 1926 Meyer attended the 6th Enlarged Plenum of the Comintern, although he faced personal criticism in that body's discussion of the German question.