Greenpeace is a group of people that care about protecting the environment and making sure animals stay safe. In 2013, Greenpeace was sailing in the Arctic on a ship called the Arctic Sunrise. The Arctic is a very special place and home to many animals and plants. However, the people who live nearby wanted to start drilling for oil in the Arctic. Greenpeace was trying to stop them from doing this, because it would hurt the animals and plants living there and also pollute the air and water.
The government of the country where the Arctic Sunrise was sailing didn't like what Greenpeace was doing, and so the government sent their own ships to stop the Arctic Sunrise. They blocked the Arctic Sunrise from leaving and stopped the people on board from leaving the ship. The government even arrested some of the people on board.
Greenpeace wasn't happy with what the government did, so they took the case to court. Eventually, a court said that the government had done something wrong and released all the people who were arrested. The court said that it was wrong for the government to stop the Arctic Sunrise and arrest the people on board.
So in the end, Greenpeace won the case and the government had to let them keep sailing in the Arctic. This meant that they could keep trying to protect the animals and plants living in the Arctic.