Sardis was once the wealthiest city in the world, under the famous King Croesus (reigned 560 546 b.c. ), hence the expression rich as Croesus. 
King Croesus bankrupted the city of Sardis.
mnli hypothesis: King Croesus bankrupted the city of Sardis. premise: Sardis was once the wealthiest city in the world, under the famous King Croesus (reigned 560 546 b.c. ), hence the expression rich as Croesus. 