This brooch comprises an aureus or gold coin, set in a plain bezel, with a pierced mount in the form of a wreath of rounded leaves. On the back of the brooch are cylindrical rings to hold a pin (now lost). The use of coins in jewellery was not a Roman invention, but their appearance in brooches, coins and necklaces becomes much more common in the Roman period, particularly from the third century AD. This may be partly due to the increasing economic instability at the time; coins of pure gold were one of the few fixed standards. Philip I (reigned AD 244-249), known as 'Philip the Arab', was born in south-west Syria, and rose through the ranks of the army until, in 243, he challenged and defeated the existing Roman emperor, the teenage Gordian III (238-243). Philip's reign was marked by a long succession of military campaigns against enemies both inside and outside the Empire. On the eastern front, in a move widely regarded as shameful, he paid off the Persian king, Shapur, with a huge lump sum, followed by annual payments. He then fought against marauding Goths who had crossed the Danube and finally against rebellious generals on the Rhine and Danube frontiers. He was eventually overthrown and murdered in 249 by the leader of one of these Danube armies, the future emperor Decius. One of the few bright spots of Philip's reign was the celebration in 248 of Rome's thousandth birthday, the thousandth year Ab Urbe Condita ('since the founding of the city').