Because they owned every step of the process to make steel like for example they owned the mines to mine the iron. Then they would own a 2nd mine to mine the coal for the steel. Then they would own the factories to make the steal. That is a vertical monopoly so for shorting your answer you can say they owned the mines and the factories to make the steel.
<span>There was a lot of trade in those Italian city-states. All of these ideas and changes in the Renaissance spread through trade. The fact that they were wealthy and could sponsor and patron new artists in the Renaissance also helped. The competition in trade in Italian city-states spurred a competition in new ideas and ways of thinking. </span>
