Individual states cannot prevent same-sex couples from marrying and must recognise their unions. That's the long-awaited ruling of the US Supreme Court, made today by a 5-4 decision. The finding that the Constitution guarantees a nationwide right to same-sex marriage is a huge victory for LGBT persons and their friends, families and supporters, coming as it does in the wake of some heartbreaking setbacks in recent years. The ruling today involved four cases in all and a dozen couples who had challenged bans in Ohio, Michigan, Kentucky and Tennessee. The Supreme Court's summary states, "The history of marriage is one of both continuity and change."

Lawyers for the plaintiffs said their clients had a "fundamental right to marry and to equal protection".

The news comes just over a month after Ireland became the first country in the world to legalise same-sex marriage by a popular vote.