As Wikipedia informs us, the word serendipity derives from Serendip, the old Persian name for Sri Lanka. It was coined by Horace Walpole in 1754 in a letter he wrote to his friend Horace Mann. The letter read,

“It was once when I read a silly fairy tale, called The Three Princes of Serendip: as their highnesses travelled, they were always making discoveries, by accidents and sagacity, of things which they were not in quest of: for instance, one of them discovered that a camel blind of the right eye had travelled the same road lately, because the grass was eaten only on the left side, where it was worse than on the right—now do you understand serendipity? One of the most remarkable instances of this accidental sagacity…”

Wikipedia tells us too that much more recently William Boyd coined the term zemblanity to mean a kind of opposite of serendipity: “making unhappy, unlucky and expected discoveries occurr by design”. This useful word  takes its name from the  the Arctic island of Nova Zembla.