Brinley Ellsworth is a British Indies Company official and childhood friend of Maharaja Duleep Singh. He turns up in London during The Last Maharaja storyline of Assassin's Creed Syndicate, where his ties to Singh put him close to the plots around the Maharaja.
Brinley distracts Singh at Buckingham Palace while a sniper takes a shot at him in A Good Shot; the twins catch the shooter. As the twins and Singh sabotage the company, the trail of attacks, including a shipment of sleeping gas bound for India, leads back to Brinley.
Brinley meets Singh in Lambeth cemetery with Blighters hidden around it. Evie kills the Blighters and knocks Brinley's gun away with a throwing knife. Singh persuades her to spare him, and Brinley leaves gloating that the Maharaja will die a trophy of war.
In The Sandman you destroy crates of sleeping gas at a factory near the Thames docks (full sync wants eight Templars knocked out by them), then tail a messenger to a carriage at the docks, where Brinley steps out and is revealed as the man behind the attacks. The Final Showdown asks you not to raise any alarm; if Evie is spotted while clearing the cemetery guards, Brinley shoots Singh.
He was recruited by the Templars while apprenticed to a British Indies Company official, and the London Templars who survived Starrick's fall called him over to England. He wants Singh dead so that India stays under British rule.
Duleep Singh
Duleep Singh, the last Maharaja of the Sikh Empire, is Henry Green's great-uncle. He helps Evie find the Buckingham Palace plans in Family Politics, and is the central figure of The Last Maharaja missions, where the twins help him fight the British India Company.
Henry Green
Henry Green is the head of the Assassins in London when the Frye twins arrive in Assassin's Creed Syndicate. He runs a curiosity shop in Whitechapel that doubles as the Brotherhood's bureau, introduces Jacob and Evie to their key allies and works alongside Evie on the search for the Shroud of Eden. His birth name is Jayadeep Mir.