great work!
I was inclined to do some research myself after reading this.
Just sharing the top results for the search:
worlds oldest currency still in use.
"The British pound is the world's oldest currency still in use at around 1,200 years old. Dating back to Anglo-Saxon times, the pound has gone through many changes before evolving into the currency we recognise today. The British pound is both the oldest and one of the most traded currencies in the world." -cmcmarkets.com
My next question is when will Bitcoin surpass the British Pound?