Complex sentence: From 1670 onwards, the Hudson's Bay Company sent two or three ships into the bay every year, bringing back furs (mainly beaver), and selling them, sometimes by private treaty but usually by public auction.
Split into simpler sentences: From 1670 onwards, the Hudson's Bay Company sent two or three trading ships into the bay every year. They brought back furs (mainly beaver) and sold them, sometimes by private treaty but usually by public auction.