Following a period of economic collapse and the following Sierra Leone Civil War inflation became rampant, devaluing older coins. A new coin series was introduced in 1996 for 10, 50 and 100 leones. The 50 leones is octagonal while the other two are round. These coins were struck in nickel-plated steel and feature important figures in Sierra Leone's political history. Ten sided, bimetallic 500 leones coins were first introduced in 2004. Of the four coins in circulation, only the 100 leones is available in small quantity due to their low valuation and shortage of supply.