Postage stamps with the inscription ST. KITTS•NEVIS were issued between 1903 and 1950. The postal and administrative histories of the two islands of Saint Kitts (a.k.a. St. Christopher) and Nevis are intertwined with those of Anguilla.
In 1903, the first stamps for St. Kitts and Nevis, inscribed ST. KITTS•NEVIS, were issued in several denominations using the British pence, shilling, and pound system. (The islands were a British colony at the time.) Occasional issues were made over the years, including some war tax stamps for the British effort in World War I.
In 1950, the island of Anguilla was incorporated into St. Kitts and Nevis; that same year, stamps of St. Kitts and Nevis were overprinted with ‘ANGUILLA TERCENTENARY 1650-1950’ to honor Anguilla’s 300th anniversary of being settled.
See also: Jamaica rare stamps for philatelists and other buyers
In 1951, stamps with a new inscription, SAINT CHRISTOPHER NEVIS ANGUILLA were issued; this name would be used (sometimes using the abbreviation ST. instead of SAINT, and sometimes using KITTS instead of CHRISTOPHER) until 1980. (Anguilla, incidentally, began issuing its own stamps in 1967, although its name would continue to appear on St. Christopher Nevis Anguilla stamps as well.)
In 1980, the last stamps for the combined islands were issued; after this, separate stamps for St. Kitts and for Nevis would be issued, although the two islands still make up a single sovereign nation.