The word 'serendipity' was invented from a 16th-century Persian fairy tale

In 1754, English writer Horace Walpole coined 'serendipity' in a letter, basing it on 'The Three Princes of Serendip' — an old tale in which the princes make lucky discoveries by accident while looking for something else. Walpole's one-off coinage sat largely unused for over a century before catching on.

— Horace Walpole, Serendipity — Coined 1754, in a letter to Horace Mann