The purpose of this doctoral dissertation is to explore the Educate Together sector, the multidenominational primary school movement in the Republic of Ireland. This multilevel exploration looks at the role of Educate Together in a pluralist Ireland, the challenges presented by the accelerated growth of the sector, the values that underpin the schools in the sector and in particular the relevance of what is termed the Core Curriculum. The background to the research is the prior work conducted with the sector in 1998. The work presented here is an account of the second phase of the research, which attempts to examine in greater detail some of the key issues that arose in the earlier work. Through a co-operative inquiry that involves a wide range of Voices within Educate Together, the research identifies a number of key issues that have arisen for the sector between 2000 and 2006. The work examines the concept of mixed schooling that underpinned the Irish National School system in the 1830’s, the gradual erosion of this system and its replacement by denominational schools and the emergence of the Educate Together sector in the 1970’s. Using a form of co-operative inquiry the research identifies the importance of Educate Together in an intercultural Ireland, the impact of this form of inclusive education on the children who attend the schools and the design and development of “Learn Together: An Ethical Education Curriculum for Educate Together Schools”. The final section of the research examines the impact of this curriculum at national and international level and in particular the strengthening of the relationship between the Colleges of Education and Educate Together. The study offers a unique insight into an important partner in Irish education.