Jacob Frye is the Assassin's Creed Syndicate twin who leads the gang known as the Rooks. He and his sister Evie Frye travel to London in 1868, during the Industrial Revolution, to challenge Templar control of the city.
Jacob forms the Rooks as a street gang and uses them to seize territory from the Blighters, a rival gang controlled by Templar forces. His approach is more direct and combat-focused, while Evie specializes in stealth and the search for an Isu artifact.
The twins are both playable protagonists, so the question distinguishes Jacob by his leadership of the Rooks. Evie is not the answer, even though she is equally central to the campaign. Assassin's Creed Syndicate was released in 2015 and is set in Victorian London.