This article investigates what effects a recognized foreign judgment in civil and commercial matters has in English proceedings. Does the judgment have the effects that it has in the foreign country (extension of effects) or the effects that a comparable English judgment would have (equalization of effects), or a combination of these? After a review of the current law, it will be discussed what approach is preferable on principle. The suggested approach will then be illustrated by considering whether a foreign decision on one legal basis of a certain claim ought to preclude English proceedings involving another legal basis of the same claim. Finally, it will be discussed whether and how the effects of a recognized foreign judgment in England are affected by interests of a third country.