This solemn 1961 issue from the Republic of Congo pays tribute to Dag Hammarskjöld, the second Secretary-General of the United Nations, who tragically died in a plane crash while on a peace mission in Africa. Each stamp features his portrait before a shaded map of Africa, symbolizing his dedication to peacekeeping on the continent. The UN emblem underscores his enduring legacy in international diplomacy. Printed by Courvoisier S.A., this elegant four-value set is a meaningful memorial cherished by collectors of UN-related and African historical issues.