The document discusses policy coherence for development (PCD) in the Organisation for Economic Co-operation and Development (OECD) system over the past two decades. It analyzes PCD promotion efforts in four time periods: 1) 1991-1993 when PCD was introduced but implementation was limited; 2) 1994-2001 when little attention was paid to PCD as OECD focused on other issues; 3) 2001-2007 when PCD gained some renewed interest but remained secondary; 4) 2007-2014 when PCD gained new impetus in OECD strategies and became a priority, though implementation challenges remain. The document examines factors driving this and the role of the European Union in promoting PCD within the OECD system.