The kwanza (sign: Kz; ISO 4217 code: ) is the currency of Angola. Four different currencies using the name kwanza have circulated since 1977. The currency derives its name from the Kwanza River (Cuanza, Coanza, Quanza). Overview First kwanza, AOK, 1977-1990 Kwanza was introduced following Angolan independence. It replaced the escudo at par and was subdivided into 100 lwei. Its ISO 4217 code was AOK. Coins The first coins issued for the kwanza currency did not bear any date of issue, although all bore the date of independence, "11 de Novembro de 1975". They were in denominations of 50 lwei, 1, 2, 5 and 10 kwanzas. 20 kwanza coins were added in 1978. The last date to appear on these coins was 1979. Banknotes On 8 January 1977, banknotes dated 11 DE NOVEMBRO DE 1975 were introduced by the Banco Nacional de Angola (National Bank of Angola) in denominations of 20, 50, 100, 500, and 1000 kwanzas. The 20 kwanza note was replaced by a coin in 1978. Novo kwanza, AON, 1990–1995 In 1990, the novo kwanza was introduced, with the ISO 4217 code AON. Although it replaced the kwanza at par, Angolans could only exchange 5% of all old notes for new ones; they had to exchange the rest for government securities. This kwanza suffered from high inflation. Coins Banknotes This currency was only issued in note form. The first banknotes issued in 1990 were overprints on earlier notes in denominations of 50 (report not confirmed), 500, 1000 and 5000 novos kwanzas (5000 novos kwanzas overprinted on 100 kwanzas). In 1991, the word novo was dropped from the issue of regular banknotes for 100, 500, 1000, 5000, 10,000, 50,000, 100,000 and 500,000 kwanzas. Kwanza reajustado, AOR, 1995–1999 In 1995, the kwanza reajustado (plural kwanzas reajustados) replaced the previous kwanza at a rate of 1,000 to 1. It had the ISO 4217 code AOR. The inflation continued and no coins were issued. Banknotes Despite the exchange rate, such was the low value of the old kwanza that the smallest denomination of banknote issued was 1000 kwanzas reajustados. Other notes were 5,000, 10,000, 50,000, 100,000, 500,000, 1,000,000 and 5,000,000 kwanzas. Second kwanza, AOA, 1999– In 1999, a second currency was introduced simply called the kwanza. It replaced the kwanza reajustado at a rate of 1,000,000 to 1. Unlike the first kwanza, this currency is subdivided into 100 cêntimos. The introduction of