Wolf's sudden resignation in early 1987 caught many intelligence analysts by surprise.
Gale resigned from this position in June 2011, citing personal reasons for his sudden resignation.
His sudden resignation prompted concerns among big shareholders that Grace might abandon its strategy.
A spokeswoman for Hearst said the sudden resignation was prompted by philosophical and policy differences.
Smith's sudden resignation on March 22 fell two months short of what would have been his 10th anniversary at Kentucky.
Several parents and guardians said that they had been satisfied with the school but were troubled by the sudden resignations.
Planned cuts have already led to the sudden resignation of his Police Commissioner.
His sudden resignation prompted concerns that the revamping might end.
There was no official explanation cited for the sudden and unexpected resignation.
But with his sudden resignation, he has also given up that post.