Ken Follett had some good novels in that vein. He also did Pillars of the Earth and World Without End, which were both phenomenal, though not what you're looking for. His century series was good and might lend itself to a limited series. It follows characters and arcs through the 20th century.
ETA It isn't all spying, but several of the characters end up in different intelligence services and political movements. The first novel explores the beginnings of WWI, the war, the aftermath, and the rise of fascism. The second one picks up with many of the same characters and their children and goes through the 30's and WWII to the brings of the cold war. The third does the same with the children of the characters from the second book, but it goes through The end of the cold war. All of them explore the politics of major world events through interaction with leaders, political figures, and intelligence agencies.
It could easily be like The Crown in its scope, but with a wider breadth of characters and more action/suspense with some of what they end up doing