This week, a group of German footballers responded to what they called a 'racial attack' on two of their team mates by 'blacking up' in solidarity.
Deinster SV, a league club from the Lower Saxony region, posted a team photo with the faces of its white players digitally altered to appear black, along with a message of what happened to the men, both Sudanese migrants.

"Violence against refugees is pathetic," the Facebook post read. "Emad and Amar, you are one of us just like everyone else and we're happy you are with us."
Sport stars have a powerful history of confronting racism and sending moving messages to combat discrimination on and off the pitch.
Here are six of the most poignant points in anti-racism in sport history:

He quickly singled her out, and to this day says he bore no anger but also that he had no regrets over asking match officials to remove her from the stadium.
Speaking after the match he said: “To hear a 13-year-old girl call me an ape… it was shattering. He added: “Racism has a face - it’s a 13-year-old girl."
The Brazilian, who also plays for his country’s national team, picked the fruit up from the floor, peeled, than ate it, before proceeding to take a corner kick.
"We have suffered this in Spain for some time," Alves said after the game. "You have to take it with a dose of humour. We aren't going to change things easily … If you don't give it importance, they don't achieve their objective."
His gesture sparked the '#weareallmonkeys' hashtag, which saw celebrities from both in and outside the sporting world tweet pictures of themselves with bananas in solidarity with Alves.

Beyoncé's half-time delivery of her new song 'Formation' saw her backing dancers wear Black Panther berets, perform black power salutes, arrange themselves into the letter 'x' for Malcolm, and hold a homemade sign (said to be unofficial) demanding "Justice for Mario Woods", the victim of a police shooting in the U.S.
Her performance sparked anger and protest among some, but it was a seminal point in drawing attention to the anti-racism cause at the biggest and most-watched sporting events ever televised.

He picked up the match-ball midway through the first half and kicked it into the crowd, then removed his shirt and was followed by both sets of players and officials.
Boateng later commented: "I'm surprised we're still hearing these things in 2013. It's not the first time in my life I've had to hear or see things like this but I'm 25 and don't want to take this any more."

African-American athletes Tommie Smith and John Carlos performed their Black Power salute at the 1968 Summer games in Mexico City.
Smith said he had raised his right fist to represent black power in America, while Carlos explained he raised his left fist to represent black unity.

In a match for St Kilda against Collingwood back in 1993, the opposition’s cheer team yelled at him to "go and sniff some petrol" and "go walkabout where you came from”.
At the conclusion of the game, Winmar lifted up his jumper and, facing to the crowd, pointed to his skin. The following day, a photograph of him posing was published in newspapers under the headline: "Winmar: I'm black and proud of it.”
His gesture has been hailed as "powerful statement", an "anti-racist symbol", and one of the "most poignant" images in Australian sport.