What  kinds  of  discoveries  prove  that  great  zimbabwe  was  a  kingdom  built  on  trade?

With an economy built on cattle husbandry, crop cultivation, and the trade of gold on the coast of the Indian Ocean, Great Zimbabwe was the literally the heart of a thriving trading empire from the 11th - 15th century.

Explanation: Great Zimbabwe was a strong, thriving city in B.C 1200 and was very well known at the time for their religion and trading center. They traded gold, cattle, and beads made of porcelain from China. This proved that their trade reached across the Indian Ocean.

the award is named for an american naval historian and theorist, rear admiral alfred thayer mahan, united states navy who, through his writing, provided stimulus and guidance to those who share in the defense of the nation.