Throwback Thursday is the name of a weekly social media posting theme where users post photos or videos that happened in the past on social networking sites like Instagram, Twitter, Tumblr or Facebook to remember a past event. Photos can be from years ago or from just a few days ago.

Throwback Thursday is very popular onInstagram, and users often tag their photos with a variety of hashtags like #TBT, #ThrowbackThursday or just simply #Throwback.

So who really started it? Check out the video below.