The Prime Ministers: Volume the Second: From Lord John Russell to Edward Heath

There is really in law no such office as that of Prime Minister. No statute grants him or her powers. Even the name came into official use only in 1878, and the Prime Minister as such only became known to the law in 1905. The office of Prime Minister has in fact been based on convention and has been shaped by personal and political factors; it is what the holder makes of it and that is why a sensible way to study the development of the office is by reading the biographies of its holders.

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