This chapter charts the demise of the regional agenda and the shift towards city-regional thinking which has underpinned much of the recent devolution agenda. Considering the similarities to the metropolitan architecture of the 70s and 80s, this discusses the emergence of Local Enterprise Partnerships through to Combined Authorities. This sets the scene for a broader discussion of the Devolution Deals being agreed at the city region level. In doing so, the chapter takes a broader look at how city regions function and, in particular, how districts can cooperate towards collective goals. This draws down recent examples from the emerging devolution deals, including how new metro-mayors are exercising their powers within their city regions, as well as lessons that can be learnt from the now nearly 20-year-old London Mayoral post.