Bosses at the social media website have published their statistics for 2015 and confirmed the message Harry posted on on 26 March (15) was the year's (15) most shared after landing more than 700,000 retweets.

Harry uploaded the note just 24 hours after Zayn announced he was walking away from the band, writing, "All the love as always. H."

Zayn's shock departure came six days after he stunned the band's devoted followers by abandoning One Direction's world tour.

The Twitter figures also show Katy Perry retained her title as the site's most popular user with 78 million followers ahead of Justin Bieber on 70 million and Taylor Swift in third place with 66.7 million.

Taylor edged out U.S. President Barack Obama, who trails behind her in fourth place with 66.5 million fans. Another pop star, Rihanna, came in fifth with 53.1 million.

European Twitter boss Bruce Daisley hailed Justin as the Twitter user to watch after he made a resurgence this year (15) with his career comeback.

"Bieber is the second most followed (on Twitter), he had 50 million followers on Twitter from when he was a teen star and he has cleverly used that.." she tells BBC Radio 1's Newsbeat. "Justin has reinvented himself using the power of social media. That's the genius of Bieber. He used a countdown with his fans, he used a wide fanbase of advocates and the social media amplified it."