Complex sentence: As multiple coins became common within a region, they were exchanged by moneychangers, the predecessors of today's foreign exchange market, as famously discussed in the Biblical story of Jesus and the money changers.
Split into simpler sentences: As multiple coins became common within a region, they were exchanged by moneychangers, the predecessors of today's foreign exchange market. These are famously discussed in the Biblical story of Jesus and the money changers.