This article presents the results of research related to analyzing the genesis of the Ganemos Zaragoza / Zaragoza in Common (GZ/ZeC) movement and its passage to constituting a political formation. Through an analysis of a survey data (n=253) and key informant interviews, we show that social movements (understood as a new social network) are born in “convoluted” social situations. To achieve this goal, we look at the theoretical view of social movements from a relational perspective. Among the main results we can see how GZ/ZeC was formed, at first, through contacts and partnerships established between preexisting social movements, that eventually ended up gaining relational support from which the movement was built and strengthened. Therefore, this text serves to understand how the process was set up for candidates in the municipal elections of May 2015.