Prince William is standing up to bullying.
"It is our collective responsibility to be alert and to be ready to challenge the behavior we see around us. We all have a role to play to ensure that we do not stand by but instead stand up and put a stop to bullying," he said in the video.
The second-in-line to the British crown appeared in a video promoting the United Kingdom's first Stand Up to Bullying Day, which takes place Tuesday.
The video and the Stand Up to Bullying campaign are the work of The Diana Award, a nonprofit organization created in Princess Diana's memory.
The organization's mission is to empower youths to reach their full potential and give back to their communities.
See photos of Prince William and Kate Middleton's recreation of Princess Diana's Taj Mahal picture:
Last month, Prince William announced the creation of a task force to prevent cyberbullying.
And last year, he visited a school and participated in a workshop with students run by The Diana Award's Anti-Bullying Ambassadors.
Celebrities including actor Ben Kingsley, guitarist James McVey and actor Jim Carter from "Downton Abbey" also participated in a Stand Up to Bullying video.
RELATED: Prince William and Kate Middleton and more of the most stylish couples throughout history: