Companies Office records show the tavern is owned by Jacob James Howell and Donald Gordon Ramsay of the same residential address in Russell.
The tavern has a bar and a garden area and says it trades seven days a week, hosting live music events and serving food.
The popularity of the name 'the Duke of Marlborough' is derived from the Duke of Marlborough who was historically the richest man in the world.
The name became particularly popular in the region of Russell (previously called Kororāreka) due to the desire to bring a perception of opulence to an area that was dubbed the "hellhole of the Pacific" by early colonisers.
This unfortunate moniker was coined due to the rowdiness of life in the area, which had become notorious for drinking, fighting and prostitution.
The Māori name of Kororāreka was replaced by Russell in the early 1840s.