International PEN was founded in London in 1921 by Mrs. C.A. Dawson Scott. Its first president was John Galsworthy. The only worldwide association of writers, its aims are to promote literature, defend freedom of expression and develop a community of writers worldwide.

Because international cultural co-operation in the field of literature and the development of understanding cannot exist without freedom of expression, International PEN acts as a powerful voice in opposing political censorship and speaking for writers harassed, imprisoned, sometimes murdered for the expression of their views.

International PEN in its early years only had Centres in Europe, but writers of other nations joined International PEN enthusiastically and, in 1926, members from fifteen nations met in Berlin. Today PEN is composed of 144 Centres in 102 countries. Its membership is open to all published writers regardless of nationality, language, race, colour or religion. Each Centre acts as an autonomous cultural and intellectual organization within its own country; individual Centres organize regional conferences and seminars; and all Centres maintain links with each other through PEN's headquarters.

Among early members were Joseph Conrad, George Bernard Shaw and H.G. Wells. Centres were soon started in Europe, with such writers as Anatole France, Paul Valery, Thomas Mann, Benedetto Croce and Karel Capek playing active parts in the life and work of PEN. Over the years members have included Nobel Prize winners and other eminent writers from all over the world; among PEN's Presidents have been Alberto Moravia, Heinrich Böll, Arthur Miller, Pierre Emmanuel, Mario Vargas Llosa and György Konrád.

PEN's highest Authority, the Assembly of Delegates, consisting of representatives from each Centre, meets at the annual PEN Congress, where, in addition to the work of the Assembly, cultural events and literary forums are held, through which seeks to mobilize the intelligence and imagination of its members in support of its ideals. The international and diverse character of International PEN is reflected in its Executive Committee, which consists of the President, the Treasurer and seven members elected from among PEN's worldwide membership.