Mebyon Peran (Cornish for Sons of Piran) is a Cornish nationalist movment violently opposed of the loss of Cornish Culture and Language, and opposed to Bristol-Rule of Wessex. Formed during the 1970's, and reformed in the 1990's, Mebyon Peran have been known to be involved in campaigns to torch Wessen owned holiday cottages in Kernowekshire, as wealthy people owning second homes put house prices up for native Cornish people, similarly to Wales in the late 1970's, early 1980's. The group are also believed to be behind a bomb attack in a Cafe in Truru in 1989, injuring ten people.
The organisation are registered as an illegal violent extremist organisation in Wessex, and the United Kingdom. The Bewitan (Wessen Police) have focused on the threat from the group since 1987, when a task force was set up in Kernowekshire for specific dealings with investigating and destroying Mebyon Peran or any similiar groups.