The Lapua movement was a group of Finnish people who wanted Finland to be independent from Russia. They were called the Lapua movement because they started in a town called Lapua. The Lapua movement started in the 1920s and lasted until the early 1930s.
The Lapua movement wanted Finland to have its own government and not be controlled by Russia anymore. They also wanted to get rid of people who they thought were against Finland and make sure that everyone was loyal to the country. They were very strict and only wanted people who agreed with them to be in power.
But the Lapua movement started to use violent methods to achieve their goals, like marching in the streets with weapons and attacking people who they thought were against them. This scared people and the government, so they had to take action to stop them.
Eventually, the Finnish government passed laws that made it illegal to be part of the Lapua movement and they arrested many of its leaders. This made the movement lose support and eventually it faded away.
In short, the Lapua movement was a group of people in Finland who wanted the country to be independent from Russia but started using violent methods to achieve their goals, which caused the government to take action against them.