In the series the incumbent in the role is a disabled male British government official (played by Patrick Newell) who uses a wheelchair.
However, during the Cathy Gale era, Steed was occasionally seen taking his orders from an individual referred to by the code-name "One-Ten", played by Douglas Muir in five episodes.
Patrick Newell had played various characters in previous episodes of The Avengers, most recently Sir George Collins, a sometime Minister of the Crown and close relative of the Attorney General, in season five's "Something Nasty in the Nursery".
In spite of his disability Mother seems mobile, continuously moving his location from more easily believable sites such as a stately home to eccentric ones such as a double-decker bus or under water.
The episode "False Witness", in which the double-decker office is featured, also implies that Mother is capable of some degree of mobility without a wheelchair, as he is seen holding a cane.
When Miss King appears as Steed's fellow professional, and they work for a fully achieved administrative character in Mother, the series loses this concrete ambiguity that had so beautifully expressed the everydayness of governmentality.
The Avengers for Modern Viewers, Michael Scott Phillips also had a negative view: "Patrick Newell does a fine job but the character himself was to be mostly a pompous windbag that would only occasionally demonstrate charisma throughout the remainder of the series.
"[2] In Alan Moore and Kevin O'Neill's The League of Extraordinary Gentlemen: Black Dossier, Harry Lime is in command of the British Secret Service acting as M but is nicknamed "Mother" by several agents, including Emma Peel.