Postage stamps and postal history of Costa Rica change in currency from "Reales" to the new Pesos and "Centavos", the issue of 1863 was surcharged with new values for postal use: 1 Centavos, 2 Centavos, 5 Centavos (all over the Medio Real stamp), 10 Centavos (over Dos Reales) and 20 Centavos (over Cuatro Reales). The 5, 10 and 20 Centavos were also surcharged "U.P.U." Costa Rican stamps were issued overprinted "Guanacaste" in 1885-89 following war with Nicaragua over the sovereignty of Guanacaste. The first issue in the new "Colón" currency was dated 1900 and put into circulation in 1901. It consists of ten stamps with values ranging from
Portuguese Timorese escudo banknotes, below) may have been due to the exchange rate from the previous currency. The 10 and 30 centavos were struck in bronze, the 60 centavos and 1 escudo in cupro-nickel, and the 3 and 6 escudos in silver. In 1964, a silver 10 escudos was introduced, followed, in 1970, by more conventional denominations of 20 and 50 centavos, 1, 2½, 5 and 10 escudos. The 20 and 50 centavos and 1 escudo were struck in bronze, with the higher denominations struck in cupro-nickel. The first banknotes, dated 1959, were in denominations of 30, 60, 100 and 500 escudos. In