The study of adolescents’ relationships with their peers has flourished over the past 30 years. At the same time, there have been marked shifts in the orientation of peer research. In the 1970s and 1980s, research tended to focus on the importance of friendship and the social status of children and adolescents within their group of peers. Key measurement techniques developed during these decades were based on selfas well as peer-reports about classmates. Since the early-1990s, however, there has been a surge of interest in dating and romantic relationships during adolescence and emerging adulthood, and this has become a significant area of developmental research by itself. By the late 1990s, renewed interest in Moreno’s (1934) framework, Sullivan’s (1953) conceptualizations, and Dunphy’s (1963) paradigmatic study, as well as many new theories of peer relationships and social development (e.g., Davila, 2008; Dishion, Spracklen, Andrews, & Patterson, 1996; Furman, Brown, & Feiring, 1999; for review, see Rubin, Bukowski, & Parker, 2006), resulted in further shifts in the focus of research. These shifts included an increasing emphasis on mapping social networks, as well as more efforts towards understanding how friendships and the peer group are related to and transform into romantic relationships (Connolly, Furman, & Konarski, 2000; Furman et al., 1999; Furman & Collins, 2009), how romantic relationships can be added and change existing friendships (Brown, 1999; Connolly et al., 2000; Connolly & Goldberg, 1999; Zimmer-Gembeck, 1999), how multiple peer-relational forms exist within peer networks, and how there are multiple ways to capture the important influential elements in even a single relational form (Collins, 2003; Connolly et al., 2000; Zimmer-Gembeck, Siebenbruner, & Collins, 2001). However, despite the broadened interests, it remains quite rare for studies of peer groups and friendships to sit side-by-side with studies of romantic relationships in a Special Issue on the peer context and peer influence. A central aim of this Special Issue was to include studies of the many aspects of adolescents’ peer relationships to show howwork in one domain adds to, and can be useful for work in another. Wewill address such synergies in our Epilogue at the end of this issue. Much of the research in this area also has undergone a transformation through the now widespread availability of statistical techniques that can capture and analyze individual factors at the same time as capturing complex group and dyad level phenomena. Such software is indispensible for researchers who need to test both group level and individual correlates of behaviors, emotions and cognitions (for a review, see Rubin et al., 2006; also see Card, Selig, & Little, 2009; Kenny, Kashy, & Cook, 2006). The sophistication of available analytical methods continues to challenge existing conceptualizations of peer relationships and contexts, and researchers may need to formulate theoretical and conceptual accounts to keep pace with the methodological developments. We include studies in this Special Issue that have used a range of established and newer techniques, while also inviting commentary to highlight the strengths, as well as the continuing limitations, of all of our methods (Laursen, 2010). Although rapid development in a field is exciting, there is a danger that conceptual integration may come to lag behind analytical advancement and that research areas continue to be split up into subspecialties that produce their own dynamics. One main goal of this Special Issue, Capturing the Peer Context, was to underscore common threads and to illustrate how current methodological developments permeate research on peer relationships at different ages and in different target