Liaisons Division
Liaisons has responsibility for dealing with external organizations. These might be other British services and agencies, foreign counterparts to the Service, and various arcane realms. Each of these have complications that must be handled with delicacy, so that the interests of the crown and the secrecy of the Service are protected.
Organization
The Liaisons Division has led by Sir Henry James Fox Bunbury for the last two years. Bunbury had previously served as Domestic Section Chief and before that as a Brigadier in the Royal Army. Prior to Bunbury, the Liaisons Director was Lord Francis Lawless, who served in the role for twenty-eight years.
Domestic
The Domestic Section primarily coordinates with the military and with law enforcement. There are permanent contacts within the Royal Navy and Royal Army, and the Metropolitan Police and Royal Irish Constabulary through the Home Office. In the latter, when something inexplicable turns up, you'll often hear a senior official say, "Give it to the funnies." In general, there is a sincere lack of amusement at anything that even remotely smells of the occult.
The Domestic Section Chief is Tyrrell Stone. He's had the job for two years and was a detective chief inspector at Scotland Yard before that.
Foreign
The Foreign Section communicates and coordinates with the Service's counterparts in other countries. In some instances, this involves the exchange of information. In others, transit might be necessary to pursue an arcane traveller. Investigators have also been seconded to other agencies. Russell Wynter's extended service in America during their civil war is an example of this.
Carter Moss is the Foreign Section Chief. He was appointed to the position in 1875. Before that, he served for ten years as Deputy Section Chief and he had spent a number of years in the Foreign Office before joining the Service.
Arcane
Formal relations with other realms has been a relatively recent development. Identifying authorities in most realms has been difficult and even then, getting them to acknowledge our status has been a fraught endeavour. Some progress has been made and while we do not yet have formal embassies in any of the realms, we do have limited diplomatic relations with several.
Alice Hargreaves (nee Liddell) is Chief of the Arcane Section. She has been in the role for five years now and served as ambassador without portfolio for the Queen in dealings with several realms in the years before that.