The Gothic art in the 14th century was supported by a culture of city councils, preaching orders (like Franciscans), and knightly culture. It was the golden age of free Dalmatian cities that were trading with Croatian feudal nobility in the continent. Urban organization and evolution of Dalmatian cities can be followed through the continued development and expansion of Rab and Trogir, the regulation of streets in Dubrovnik, and the integration of Split. It was also when streets in this region were paved with stone, sewage canals were re-developed (the Byzantine Empire retained flushing toilettes, whereas this technology was lost in Roman Catholic Europe), and communal facilities were re-established.