The chapter describes the evolution of policy in London since the end of the last century and argues that landscape ecology, and its practical application through the policy and practice of green infrastructure approach. The driver for promoting green infrastructure in London, particularly East London, was the advent of the Thames Gateway initiative, a major urban regeneration initiative originally conceived by the Conservative Government in the 1990s but not fully implemented until the launch of the Sustainable Communities: Building for the Future. Borrowing from the American approach to green infrastructure by encouraging the incorporation of functional green spaces and features into buildings and streets to manage storm water and improve water quality. In order to steer this investment and to ensure private sector contributions, a green infrastructure policy was published, possibly for the first time in the UK, as the East London Green Grid and updated and expanded to cover all of London in the All London Green Grid (GLA 2012).