The ancient Celts were a people of the forest. They used a lot of wood in their daily lives, for housing, cookery and art. Sometime around the 5th century BC, they came up with an ingenious new way with wood; they formed it into barrels, for storing liquids such as water, ale and, eventually, when this craft was bequeathed to the modern age, wine.
Wood buckets for food preparation and storage long predated the closed-end barrel, but nothing beat the latter for moving liquids from one place to another – just across the winery cellar, for example, or down river to an export dock. Wood barrels were large, hollow wooden wheels, strong and reusable.