The year of the film we see is 1997 when a secret agent sacrifices his life and save his team during the raid in the country of Middle East. Galahad or Harry Hart takes the responsibility of his death and arranges to deliver a medal of valour to his family. The secret agent has wife named Mechelle Unwin and son Gary Eggsy.
He also keeps a message that if she needs any help, then she can call the phone number printed on the back side of the medal. The film leaps after seventeen years. James Arnold is a professor and he is kidnapped by the billionaire Richmond Valentine. Lancelot is the agent working for Hart and he tries to get the professor back, but during his attempt he is killed by Gazelle who is working as hench woman for Valentine. Eggsy is spending hard life in London and can’t find any job. His mother is now married to Dean and he also has a step-sister.