In 1434, the Ruthenian domain of the Crown was transformed into the Ruthenian Voivodeship. In 1444, the city was granted the staple right, which resulted in its growing prosperity and wealth, as it became one of the major trading centres on the merchant routes between Central Europe and Black Sea region. It was also transformed into one of the main fortresses of the kingdom, and was a royal city, like Kraków or Gdańsk. During the 17th century, Lwów was the second largest city of the Polish–Lithuanian Commonwealth, with a population of about 30,000.