Northern Ireland stands out as having enacted historical positive change in abortion law, from an almost complete ban in the 20th century to the decriminalization achieved in 2019. This book documents and analyzes how this historical change was achieved. Each chapter is written by those directly involved in the long-fought battle to change abortion law - including those with personal experience of seeking abortions, activists, academics, legal experts, political actors, NGOs, and volunteers. In this, the first of two volumes, contributions focus on the legislative landscape of the process with particular emphasis on the importance of 'feminist legal work' - law-making influenced by the women most likely to be impacted by it. Decriminalizing Abortion in Northern Ireland is a deep dive into the long road to decriminalisation, spanning two volumes and a timeline of decades ? These two volumes tell the rich history of the abortion rights movement in NI, and how a constellation of movements and actors came together to achieve decriminalisation. They are a must-read for anyone researching abortion rights, and for those unfamiliar with the NI context, provide a thorough introduction.