The words in this list are very close in meaning, each being most strictly applied to a person from whom one is descended. Ancestor , forbear and forefather are hardly ever applied to parents or grandparents, whereas progenitor is sometimes applied to them as well as to more remote ancestors .

• Although Napoleon and his immediate progenitors were Corsicans, he is considered by most modern Frenchmen to have been as French as their own ancestors .

Ancestor and progenitor are often applied to things other than people.

• Eohippus is an ancestor of the horse; The progenitors of Italian lyric verse forms were those used by the troubadours of Provence.

Progenitor , in this sense, points to an early form that created, caused or led to the development of a newer one; ancestor , even in this extended sense, retains the idea of historical evolution, the course of which is determined by forces over which man has no control and little knowledge.

• The impressionist movement was one of the ancestors of abstract art; Johnson’s dictionary was the progenitor of many others that followed its style and treatment of the language.

Forefather and forbear are usually used in the plural. Forefathers is most often used in a poetical context and frequently connotes strong family or racial feeling, or continuing habitation in one place, whereas forbears has such connotations to a much smaller degree.