The various bronze alloys (and brass alloys as well) are discussed along with a brief historical overview of their development. The complexity of the copper corrosion processes is stressed; the corrosion taking place under burial conditions, corrosion caused by air pollution, and corrosion problems caused by peculiarities in the casting or gilding methods are all discussed. The difference between patina and corrosion is explained. Methods for treating corrosion (mechanical, chemical, and electrochemical) are summarized. The protective measures of proper storage, coatings, and periodic care are explained.