The Thames gang war is the fight for ownership of the river borough against Edith Swinebourne's Blighters. Win the brawl and defeat Swinebourne to put the Thames under the Rooks.
Swinebourne joins the fight after some losses and is killed, and the Thames passes to the Rooks.
The Thames has no strongholds and no factory, so its war opens through bounties and Templar hunts alone: the bounties on Simon Chase, Emmet Sedgwick and George Scrivens and the hunts on Captain Hargrave II, the Jekyll brothers and Tom Eccleston.
Swinebourne is shown injecting herself with a berserk dart as the fight starts, so expect her to come in aggressively once she shoves her way through her own Blighters. Thin her gang so she cannot rely on numbers when she arrives.
Several of the targets on the river answer to her directly: the Jekyll brothers mention her visiting to thank them for arming the Blighters, and the bounty Simon Chase asks whether she sent you.
Gang War: City of London
The City of London gang war is the street fight that decides the borough once you have weakened Bloody Nora's Blighters. Accept the challenge from the messenger, beat her gang and then Nora herself to make the City Rook territory.
Gang War: Lambeth
The Lambeth gang war is your showdown with Cletus Strain's Blighters for control of the borough. The messenger warns that Strain is a bit sadistic; defeat his gang and then Strain to take Lambeth.
Gang War: Southwark
The Southwark gang war pits the Rooks against Octavia Plumb's Blighters, who accept the challenge only reluctantly. Win the brawl and defeat Plumb to claim Southwark.
Gang War: The Strand
The Strand gang war is the decisive fight against Victor Lynch's Blighters. Lynch agrees to the terms on condition that he fights with electrochemical bombs, so expect explosives once he joins.