Complex sentence: When Riemon Soga, Masatomo Sumitomo's brother-in-law, learned purportedly Western methods of copper refining he established a smelting business in 1590, Izumiya, literally meaning "spring shop".
Split into simpler sentences: When Riemon Soga, Masatomo Sumitomo's brother-in-law, learned purportedly Western methods of copper refining, he established a smelting business in 1590. This he named Izumiya, literally meaning "spring shop".