Complex sentence: Contact between Canada and Korea dates back to the 19th century when Canadians were some of the first Westerners to arrive on the Korean peninsula, a majority of whom were Christian missionaries, though they branched out into other fields of work.
Split into simpler sentences: Contact between Canada and Korea dates back to the 19th century when Canadians were some of the first Westerners to arrive on the Korean peninsula. Most of them were Christian missionaries, though they branched out into other fields of work.