It's been described as an important, influential relationship in royal circles but one half is always hidden from view.
In his new book, Valentine Low, Royal Correspondent with The Times, delves into the work of the courtiers and discovers what really keeps the royal machine working.
As 'Courtiers' is published, Royal Central's Sydney Zatz spoke to Valentine Low about this all important royal relationship and the future of the monarchy. And she heard his thoughts on how traditional King Charles will be and how Prince William could be shaping up as a royal 'revolutionary'.
Find out more in our special edition podcast, the first of a new series of interviews around the Coronation and the new reign of King Charles III.