Elche's history dates back to the 5th century BC, as an iberian setlement. The iconic Lady of Elche (currently hosted in the National Archeological Museum in Madrid) has been dated between the 5th and 4th century BC.
When the romans took the city they called it Ilici, being the demonym ilicitanos still in use to refer to the inhabitants of the city.
Under muslim rule new irrigation systems were introduced, allowing the creation of an oasis in Elche. In honour to the holy city of Medina, founded next to an oasis with palm trees, the city of Elche started its singular palm grove at the end of the 10th century AC. Even being a muslim symbol the oasis was respected when the city passed again to christian's hands due to its economic value.
Courtesy: Wiki Travel