It's been eight years since the formation of one of the world's most successful boy bands.

Now, the One Direction lads each boast successful solo careers since the group went on an indefinite hiatus in January 2016.

This didn't stop fans celebrating the band's eighth anniversary, actively participating in an #8YearsOfOneDirection tag on Twitter.

Some of the band members themselves decided to weigh in and thank fans for supporting both the band and their solo endeavours.

#8YearsfOneDirection Wow! 8 years of amazing memories with the lads . Thank you so much for standing by us for all this time.

— Niall Horan (@NiallOfficial) July 23, 2018

#8YearsOfOneDirection Where has the time gone!? Thank you so much to every single person who’s ever supported us. Big love!

— Louis Tomlinson (@Louis_Tomlinson) July 23, 2018

And remember if it’s by one direction and it’s a banger I probably wrote on it 😝 #8YearofOneDirection

— Louis Tomlinson (@Louis_Tomlinson) July 23, 2018

#8YearsOfOneDirection what an incredible 8 years it’s been with my brothers! Thank you to all the fans that are still supporting and following our journeys. Love LP ❤

— Liam (@LiamPayne) July 23, 2018

The One Direction Twitter account itself is also in celebration mode, having tweeted out lyrics from some of the band's hits all day.

A whole lotta history... this Monday is an important anniversary for the guys, it’s been #8YearsofOneDirection

To celebrate, it's time to relive all the hits this weekend by streaming the official playlist and tweeting which tracks you are listening to https://t.co/H09htTye18 pic.twitter.com/Pus8wudY7T

— One Direction (@onedirection) July 20, 2018

Since the band went on hiatus, Niall Horan and Harry Styles have released solo albums (Horan's Flicker and Styles' self-titled debut) which they've toured. Styles has also starred in Oscar-winning drama Dunkirk.

Louis Tomlinson and Liam Payne have released singles both solo and in collaboration with other artists. Both are expected to launch solo albums later this year, while Tomlinson has also been revealed as a judge for the upcoming season of X Factor UK.

Meanwhile, Zayn Malik, who departed the band in 2015 before its hiatus, is gearing up to release his second solo album. His first LP Mind of Mine achieved commercial success (debuting at number one on the UK Albums Chart) and was well-received by critics.

What better way to reminisce than with the 'History' music video?