Included in Twitter's comprehensive review of the year are the ten most retweeted tweets of 2015.
The top ten is mostly One Direction members speaking to each other, but it also features Barack Obama, the king of Saudi Arabia and Kanye West.
Caitlyn Jenner introduces herself to the world.
This was Leonard Nimoy's last tweet. He died in February aged 83.
After being crowned ruler of Saudi Arabia, King Salman tweeted this prayer:
This was Barack Obama's response after the US supreme court effectively legalised gay marriage.
This was the year Zayn Malik quit One Direction. He tweeted praise for their new song 'Drag Me Down'.
This tweet by Harry Styles after Zayn quit the band, a message of thanks to One Direction's fans, was the most retweeted of 2015. It has fewer retweets than Obama's 'four more years' tweet, and Ellen DeGeneres' Oscar selfie from previous years.
Find out more about a year on Twitter here.