Robert C. Gilman is a thinker on sustainability who, along with his late wife Diane Gilman, has researched and written about ecovillages. The Gilmans’ work was important in giving definition to the ecovillage movement and shaping the direction of the Global Ecovillage Network. In 1991, the Gilmans co-authored Eco-Villages and Sustainable Communities, a seminal study of ecovillages for Gaia Trust. Also in 1991, Gilman, who was publisher of the magazine In Context, wrote an article entitled “The Eco-village Challenge” that set out a definition of an ecovillage as a: human-scale full-featured settlement in which human activities are harmlessly integrated into the natural world in a way that is supportive of healthy human development and can be successfully continued into the indefinite future. [1]This definition was to become the standard definition on which the ecovillage movement was founded and is still considered by many to be the most authoritative.