فرناندو الثالث ملك قشتالة
The city's name, which means "two sisters", dates from its founding in 1248 by King Ferdinand III of Castile and honours Elvira and Estefanía Nazareno, the two sisters of Gonzalo Nazareno, one of the king's principal military commanders. For this reason natives of Dos Hermanas are called "nazarenos/as".