The Bitcoin Standard: The Decentralized Alternative to Central Banking

by Saifedean Ammous

Under the reign of Caracalla (AD 211–217), the gold content was further reduced to 6.5 grams, and under Diocletian (AD 284–305) it was further reduced to 5.5g, before he introduced a replacement coin called the solidus, with only 4.5 grams of gold.