[3] Sources sometimes identify her as Bertha Braunthal-Clark, reflecting her marriage in or before 1933 to the Scottish born communist Willie Norby Clark.
Braunthal became a member of the breakaway Independent Social Democratic Party ("Unabhängige Sozialdemokratische Partei Deutschlands" / USPD).
After the war ended, at the Party Conference which took place at Leipzig in December 1919, she was one of six people elected to the secretariat of the USPD Central Committee.
[4] As further realignment of the political left approached, in October 1920 she attended the "breakup party congress" ("Spaltungsparteitag") in Halle and was elected to the four person Secretariat of the USPD Central Committee.
[7][8] During this period she was working alongside Clara Zetkin, Hertha Sturm and Martha Arendsee editing the party newspaper, Die Kommunistin ("The Woman Communist").
[2] Later Bertha Braunthal-Clark and her Scottish born husband worked together on the Comintern newspaper Inprekorr ("International Press Correspondence") which had been set up in 1921 by Gyula Alpári.
[4] According to one left-leaning source, Willie and Bertha Clarks were subject to constant surveillance by the British security services after they moved to London,[4] and there is certainly a file with their names on it.