Ancient cultures across the world developed bronze-casting techniques, including those in India, Africa, South America, China and Greece.
The lost-wax casting process, also known by the French term "cire perdue," was for centuries the most common technique for casting bronze. The sculptor made a sculpture with clay or wax before forming a mold. To form a bronze shell, the sculptor placed a heat-proof sculpture inside the mold coated by a thin layer of wax. With heat the wax melts away, leaving space to pour the bronze and form a shell. For a solid piece, the wax-filled mold was fired in a kiln and the wax melted away, leaving the full cavity to be filled with liquid bronze.
Bronze is particularly good for casting, because it expands slightly just before it sets. This expansion allows bronze to catch fine details from a mold--the reason for the popularity of bronze for sculptural casts.
Sculptors use bronze for a number of reasons. Unlike marble or other stones, hollow bronze is lighter in weight and allows for long extensions of limbs. Roman marble copies of Greek bronzes, for example, must often include ugly tree stumps or other devices to support the figure. Bronze is much better for sculptural compositions that have long extensions and greater negative space, as stone and terracotta break off easily.
Bronze is now mainly used for sculpture, as it is not as abundant as iron or as effective as steel for weapons, utensils and other utilitarian objects. Bronze, like other metals, doesn't necessarily last a long time, since cultures in times of war will melt down sculptures for weapons or to make money.
Other than the risk from human cultures, bronze preserves rather well.
Bronze usually only undergoes surface oxidation. Once copper oxide forms on the surface of bronze, the underlying metal is protected, unless copper chlorides form (which will destroy bronze).
Bronze resists corrosion and metal fatigue (structural damage that occurs through constant use) more than steel. It is particularly resistant to seawater corrosion. For example, the Riace bronzes made by the Greeks in 460-430 BCE sat underwater until their discovery in 1972--and are still intact.
Bronze doesn't create much friction with other metals. Manufacturers often make cast-bronze fittings such as springs, bushings and bearings--any part that touches other metal parts in a mechanical system.
Bronze also does not create sparks when struck against another metal. Many use cast-bronze hammers, wrenches and other tools for use around flammable gases.