For over 500 years, people across the world have used small pig-shaped containers to save their coins. Historians think these piggy banks have been invented several times, in different places - both for good luck and as a muddy coincidence. In the 13th century in Java, Indonesia, piggy banks were based on a type of boar called caleng. These were plump and symbolized prosperity. In 16th century Britain, coin boxes made from a muddy clay were called pygg. You smashed them to get your money out. Over time the words pygg and pig got more and more similar and piggy banks were born.