Spade Money

Spade money (Chinese bu) is the name given to the cast bronze money of ancient China that was shaped like a small digging spade or hoe. It circulated in the states of the Zhou period, chiefly in the central and northern plains, from roughly the seventh century BCE until the unification of China under Qin in 221 BCE, and it is one of the earliest forms of metal currency anywhere in the world.

Spade money grew out of the exchange of real agricultural tools, which were valued goods in a farming economy. Over time the tool became a token: the blade grew thin, the handle shrank and the object ceased to be usable for digging, but it kept its familiar outline as a recognisable form of money.

Before metal money, exchange in early China relied on barter, on prestige goods such as jade and silk, and on cowrie shells. Bronze tools were useful, durable and widely wanted, which made them a natural medium of exchange. Scholars generally see the first spade-shaped money as a direct imitation of these tools, cast in bronze specifically for payment rather than for work.

The earliest monetary spades kept a hollow socket into which a wooden handle could, in principle, have been fitted. These are dated by most specialists to the Spring and Autumn period (770–476 BCE), although exact dating of individual types is still debated.

Numismatists group spade money by the shape of the handle and the feet. The main families are:

• Hollow-handled spades (kongshou bu): the oldest group, with a socketed handle, often found in the Zhou royal domain and neighbouring states.
• Flat-handled spades (pingshou bu): thinner, lighter pieces typical of the Warring States period (475–221 BCE), cast in a solid flat form.
• Pointed-foot, square-foot and round-foot spades: sub-types named after the outline of the lower edge, associated with particular regions and states.

Most spades carry short inscriptions in early Chinese script. These usually name the town or city where the piece was cast, and some also give a weight or value expressed in the unit jin. The place names are a valuable source for the historical geography of the period, since they record hundreds of towns in the states of Zhao, Wei, Han and Yan.

Spades were cast rather than struck. Molten bronze was poured into moulds of clay or stone, and many original moulds have been excavated at foundry sites. Because production was in the hands of individual states and cities rather than a single ruler, weights, sizes and alloys varied considerably. This decentralised casting set Chinese money on a different technical path from the struck coins of Lydia and Greece, such as the Lydian stater, which appeared at broadly the same time.

Spade money was a cash instrument for everyday trade and tax payments in its home regions. It shared the Warring States economy with other forms: knife money in the east and north-east, cowrie-shaped bronze pieces in the southern state of Chu, and the round huanqian that spread from the fourth century BCE. Hoards often contain a mix of local and foreign pieces, showing that different monetary zones overlapped and that money moved along trade routes between states.

Because each state controlled its own casting, a state could profit by issuing lighter pieces, an early form of seigniorage. The gradual thinning of spades over time is often read as evidence of this pressure, a pattern later repeated in many systems of currency debasement.

After the First Emperor unified China in 221 BCE, the Qin government made its own round coin, the ban liang, the standard bronze currency and abandoned the regional shapes. Spade money then fell out of use. It was briefly revived as part of the monetary reforms of Wang Mang (9–23 CE), who issued spade-shaped pieces alongside round coins, but these did not outlast his reign.

The round coin with a central hole, refined in the Han wu zhu, became the long-term model for Chinese money. Spade money nonetheless left a trace in language: the character bu continued to appear in later monetary vocabulary, and spade shapes are still used as motifs on charms and in modern design. For collectors and historians, spade money is a reminder that coinage did not start in a single place, and that China developed its own monetary tradition independently of the Mediterranean world.

• British Museum – Collection online
• American Numismatic Society