When did the term "leadership" get this so widespread use in such contexts? I have studied and worked in universities, and I used to know the head of the depart

When did the term "leadership" get this so widespread use in such contexts? I have studied and worked in universities, and I used to know the head of the department as the head of the department. Now in my last department the head of the department is "the leadership" and the bunch of managers and admin people around them is "the leadership team" and this is how they go around, introduce themselves and sign their emails. They radiate all the madness and narcissistic vibes that the author describes. And the talk has become all this corporate blah blah void of real content stuff, with all that jargon as if they forgot how to talk like actual people and as we have all forgotten what we actually do. It is all madness. I have heard similar from other departments, so I do not think we are the only ones. So, anyway, when has the word "leadership" started becoming more widely used to describe essentially "management"?