Secretary of State for Canada
The secretary of state for Canada, established in 1867 with a corresponding department, was a Canadian Cabinet position that served as the official channel of communication between Canada and the British government in London. As Canada became increasingly independent after World War I, and particularly with the passage of the Statute of Westminster in 1931, this role fell into disuse.
Source: Wikipedia — Secretary of State for Canada (CC BY-SA 4.0)