The study of memory has become increasingly transnational. Central to this cross-border focus has been the recognition that the national and transnational are not easily separated. Key theoretical terms have been developed to described this entanglement, as ‘multi-directional’, ‘travelling’, ‘transcultural’ or even ‘global’. This chapter shifts the focus to consider how memory is developed relationally. It analyses not how memory moves across borders, or how it is received and put to use in different contexts; instead, it looks at how memory is actively built at points of ‘intercrossing’. It does this by examining the cross-border co-operations of two memory-political institutions located in Germany (Memorial Berlin-Hohenschönhausen and the Federal Office for the Stasi Files) over a four-year period. Using an innovative methodology that combines the quantitative approach of social network analysis with a discursive analysis of published texts, the chapter shows how these institutions use collaboration across borders to construct memory regions and to support or contest national memory regimes. It concludes by proposing the new theoretical concept of collaborative memory. Collaborative memory focuses our attention on the agents of transnational memory cultures and incorporates acts of memory that are constructed through co-operative action between partners in different national contexts.