Serendipity is a word that was coined by the English writer Horace Walpole in the mid-18th century. Walpole based the word on the Persian fairy tale The Three Princes of Serendip, in which the protagonists are continually making fortunate discoveries by chance. In English, the word has been used since the late 18th century to describe the occurrence of happy or beneficial events by chance or accident. Today, serendipity is a commonly used word in English, and is often associated with unexpected discoveries or happy accidents.