The words 'insure,' 'ensure,' and 'assure' were once the same word, and their separation tells the story of an industry being born. All three descend from Latin securus (free from care), through Old French seur (safe). Anglo-Norman enseurer meant simply to make safe or certain, and when it entered Middle English, the spellings 'ensure' and 'insure' coexisted as interchangeable variants for centuries. The decisive split came in the late 17th century when London's commercial revolution created a need for precise financial terminology. Ship owners gathering at Edward Lloyd's coffee house from the 1680s began using 'insure' specifically for the arrangement of financial protection against maritime loss. As the insurance industry formalised, the word followed suit. By the 18th century, 'insure' had claimed the commercial territory exclusively, while 'ensure' retreated to the general sense of making certain. American English sharpened this division further; British English occasionally still uses 'insure' in the broader sense, but the financial meaning dominates worldwide.