What is the relationship between British empire and pound sterling in the context of the input sentence. Choose an answer from: product/material produced; manufacturer; distributed by; industry; position held; original broadcaster; owned by; founded by; distribution format; headquarters location; stock exchange; currency; parent organization; chief executive officer; director/manager; owner of; operator; member of; employer; chairperson; platform; subsidiary; legal form; publisher; developer; brand; business division; location of formation; creator.

Yet London wasn't always king of forex: The hegemony of the pound sterling in the British empire meant that before 1914, London played second fiddle in forex to Paris, Vienna, Berlin and New York.

Answer: currency