Anna Wintour has taken to Twitter for the first time, and was compelled to do so to congratulate the US on two Supreme Court rulings in favour of equal marriage.

Yesterday, the federally-sanctioned Defense of Marriage Act (DOMA) was struck down in the Supreme Court for being unconstitutional.

The court also effectively struck down Proposition 8, the US State of California’s ban on same-sex marriages, by voting not to take up the case, and therefore deferring to a district court’s ruling.

The Vogue Editor took to the microblogging site, using the magazine’s official account to tweet its 2.6 million followers a message of support for Wednesday’s groundbreaking Supreme Court rulings around DOMA and Proposition 8.

The tweet by the 63-year-old was favourited 302 times, and was retweeted 593 times.

The tweet was the first by Ms Wintour, who is not expected to use the site again any time soon. Her UK and Italian counterparts tweet on a daily basis.

Speaking to Ad Age, a Vogue spokesperson said it was Ms Wintour’s idea to send the tweet. She said: “Anna has always been vocally committed to the cause of marriage equality.”

Leonardo DiCaprio also tweeted a simple message of congratulations, saying: “Historic day. Well done #SCOTUS.”

Many large brands, including Apple, GAP, Microsoft, Smirnoff, Marc Jacobs, MasterCard, and many others also came out to show their support of the decision.