Complex sentence: This strategic location was decisive in Barcelona's growth, for the city became established as a trading point between the two worlds and, eventually, the greatest maritime power in the Mediterranean, despite not possessing a port worthy of the name.
Split into simpler sentences: This strategic location was decisive in Barcelona's growth, for the city became established as a trading point between the two worlds and, eventually, the greatest maritime power in the Mediterranean. Barcelona dominated the Mediterranean despite not possessing a port worthy of the name.