jats:titleAbstract</jats:title>jats:pThis article looks at successive attempts to create new spatial imaginaries around three estuary‐based city regions in England: the London–Thames Gateway, the Atlantic Gateway/Mersey Belt (Manchester and Liverpool), and Hull and the Humber ports. We develop a framework of analysis for new planning and regeneration spaces that takes forward debates on relational and territorial geographies, spatial imaginaries and the creation of new regional identities as governance objects. Specifically, we adopt a long‐term and comparative perspective that allows an examination of how successive efforts at regional building are both path‐dependent and context‐specific, as new approaches reflect emerging ideas about how best to construct successful regions in a changing global economy.</jats:p>