Development has long been a field of epistemic debate. Where do the ideas and knowledge that underpin the practices and approaches of international development come from? Who generates and who promotes them, and why? Do ideas really matter at all - or does the practice of development carry on 'business-as-usual' while conceptual fads come and go on grant applications? And crucially, how do these evolving ideas shape broader societal worldviews?This book investigates the creation, spread and contestation of ideas within global networks of development organizations and the communities they work with. To do so, it draws on multi-spatial ethnographies of two globally interconnected networks - one linking an American family foundation, Kenyan non-profits, community-based organizations, and grassroots activists, the other connecting a global foundation headquartered in Switzerland, Kyrgyz NGOs, and village working groups. Both networks revolve around ecological projects intended to support pastoralist communities affected by climate change, yet both engage in many other realms of knowledge, including understandings of the state, land rights, rural livelihoods, expertise, authenticity, participation, and development itself. Civil Society Knowledge Networks simultaneously traces the contestation and power of ideas, the epistemic inner-workings of international development, and linkages between global, meso, and local scales via development-focused civil society. It advances the concept of civil society knowledge networks to make sense of the way development can act as a vector for the diffusion of ideas and worldviews, and the ways in which development practice is itself shaped by this process. In so doing, the book challenges assumptions about the way power is distributed between development institutions and communities by tracing the way local actors can challenge the epistemic authority of elite global institutions by laying claim to categories of authenticity and legitimacy.This is an open access title available under the terms of a [CC BY-NC-ND 4.0 International] licence. It is free to read at Oxford Scholarship Online and offered as a free PDF download from OUP and selected open access locations.