The terms social entrepreneur & social entrepreneurship were first used in the literature on social change in the 1960s and 1970s . It came into widespread use in the 1980s and 1990s, promoted by Bill Drayton the founder of Ashoka: Innovators for the Public, and others such as Charles Leadbeater. From the 1950s to the 1990s Michael Young was a leading promoter of social enterprise and in the 1980s was described by Professor Daniel Bell at Harvard as 'the world's most successful entrepreneur of social enterprises' because of his role in creating over 60 new organizations worldwide, including a series of Schools for Social Entrepreneurs in the UK.

Although the terms are relatively new, social entrepreneurs and social entrepreneurship can be found throughout history. A list of a few historically noteworthy people whose work exemplifies classic "social entrepreneurship" might include Florence Nightingale (founder of the first nursing school and developer of modern nursing practices), Robert Owen (founder of the cooperative movement) and Vinoba Bhave (founder of India's Land Gift Movement). During the 19th and 20th centuries some of the most successful social entrepreneurs successfully straddled the civic, governmental and business worlds - promoting ideas that were taken up by mainstream public services in welfare, schools and healthcare.

http://en.wikipedia.org/wiki/Social_entrepreneurship