I've been reading Machiavelli's The Prince out of curiosity - to see if there is anything relevant to modern organizational leadership.
If you tiptoe through the Realpolitik and sidestep the recurring need for Princes to slaughter whole towns to prove they are not to be trifled with, you can find some interesting stuff relevant to leading Mergers and Acquisitions and one or two other modern leadership problems.
But, overall, Machiavelli is a bit too literal on reducing headcount to be of much use today.
Then I came across this:
"There is nothing more difficult to plan, more doubtful of success, nor more dangerous to manage than the creation of a new system. For the initiator has the enmity of all who would profit by the preservation of the old institutions and merely lukewarm defenders in those who would gain from the new one."
That was written in 1513.
Nothing new under the sun.