Are the Middle East's two heavyweights, Turkey and Saudi Arabia, friends or foes? What are the main drivers behind their rivalry or cooperation? The nature of their relationship has region-wide repercussions, affecting the calculations of both regional and global actors. This book is the first to offer a comprehensive and nuanced examination of the main drivers in the complex relationship between Turkey and Saudi Arabia, focusing on the role of domestic, regional and international dynamics. Three decades are examined: the 1990s, the 2000s and the 2010s. Thus a review of the recent history of the relationship outlining the background dynamics goes on to identify the key turning points in the post- 2011 Middle East, in which the two states have frequently found themselves on a collision course due to their widely differing domestic, regional and international agendas.