Tanqueray is a London Dry Gin, so called because of the distillation process, not the origin of the product and is primarily produced in Scotland for export to its largest market, the US.
London Dry Gin is made through double distillation of a neutral grain spirit with botanicals added during the second distillation.
Tanqueray Gin is one of the iconic gins of the world and claims an unchanged recipe for 130 years.