The aim of this study has been to explain the breakthrough of the green party, Miljøpartiet de Grønne, in the 2013 parliament elections in Norway. This is carried out by an in-depth case study of the party. By using an agency-centered perspective, the assumption is that the party can influence their own ability to achieve entry into parliament. Therefore this study focuses on the party’s actions, specifically the strategies used by the party. I have studied the party’s strategies in three different areas: resources, policies and relations with other parties. This has been carried out by analyzing a large amount of different texts using both qualitative and quantitative methods. My findings show that the party was most successful with their resource and policy strategies. They succeeded in recruiting members and building up the organization of the party, increase the party’s media space and challenge the other parties in environmental policies.