This paper explores the capacity for objects entangled in complex - and often painful - histories to become constituted of multiple agencies (Gell 1998) through their interaction with various actants in complex and ever-expanding networks of association (Latour 1993; 2005). It does so by analysing how such objects become symbols for multiple histories, presences, and political agendas throughout their social lives (Appadurai 1986; Kopytoff 1986). The paper also examines how these objects influence and construct the pathways of their social lives through their polyagency. ‘Polyagency’ reflects a theory of object agency that I have developed through engaging literature on materiality and agency (Gell 1998), consumption and object movement (Appadurai 1986; Kopytoff 1986), and networks of relationality (Latour 2005). It considers the multiple gathered identities that objects come to embody through the sum of their interactions with various human actors during the objects’ social lives - agencies which then become efficacious in later interactions with people. The productivity of this theory is demonstrated by applying it to the analysis of a complicated repatriation case involving the Gweagal Spears, currently owned by Trinity College and held at the Museum of Archaeology and Anthropology in Cambridge. This application illustrates the impact that innovations in theory and repatriation cases can have on the perceived role of museums regarding object return, decolonisation and reconciliation efforts through relationship-building with source communities.