In this presentation Olaf Janssen - project & account manager at The European Library - talks about 18 years of cooperation between the national libraries of Europe. He introduces national libraries in a European context and presents the history and benefits of their collaboration. He outlines the development of The European Library (TEL) from the Gabriel project and the TELproject, and discusses how the TEL-ME-MOR project contributes to the growth of TEL. I held this talk as an invited speaker during the NLB Conference "Celebrating Knowledge, The Power and Potential" on 15-11-2005, Singapore