In: Jahrbuch für Historische Kommunismusforschung 2016. Berlin: Metropol Verlag, pp. 217–234.
On one side there is the primary school teacher Hugo Urbahns; on the other, the dockworker Ernst Thälmann. In the early 1920s they were the two most influential communists in the port city of Hamburg. Whilst Urbahns was leader of the KPD district of Wasserkante, Thälmann led the group in Greater Hamburg. Both played a prominent role in the Hamburg rising in the year 1923. Yet, they were already sworn enemies, and remained so – including after Thälmann became the leader of the German Communist Party (KPD). In the meantime, Urbahns had become leader of the ‘Left Opposition’ faction, and was subsequently expelled from the KPD. Existing research has it that during their Hamburg period both belonged to the party left. Their quarrels were purely of a personal nature and due to their very different temperaments. However, a close analysis of Urbahns' role in the Hamburg KPD's early years (1919–23) based on original sources illustrates that their disagreements were of a political nature and occasionally even took on the form of faction fights.