Former San Francisco 49ers quarterback Colin Kaepernick has made waves with his national anthem protest, which he started in August 2016—about a month after police shot and killed Alton Sterling and Philando Castile, and two years after the Black Lives Matter movement gained national attention.

To be clear: Kaepernick’s intention was to protest social injustice and police brutality. He said it best in a 2016 interview on KTVU-TV: “There’s a lot of things that need to change. One specifically is police brutality. There’s people being murdered unjustly and not held accountable. Cops are getting paid leave for killing people. That’s not right. That’s not right by anyone’s standards.”

Check out the above video to see why Kaepernick decided to take a knee.