Greenleaf had a nearly 40-year career with AT&T telephone company, including as a manager. In retirement, his work as a consultant for businesses, universities, foundations and churches allowed further observations of how organizations worked. His first published essay, The Servant as Leader (1970), is his most popular work. There and in his other writings he suggests "the need for a new kind of leadership model: a model the puts serving others first — including employees, customers, and community."
(Greenleaf, 1996, p. 4).