There is evidence that Santomera had already been inhabited by the Argaric Age, and since then it has been populated by Carthaginians, Romans, Berbers and Arabs and formed part of the county of Orihuela and later of the Kingdom of Todmir.
However, the first historical documents which refer to it appear after the Reconquest, it being mentioned in the chronicles of Alphonse X The Wise. King Jaime I found lands which had been almost abandoned and had to repopulate them with people from Aragon and Catalonia, which produced confrontations with the Kingdom of Castilia, as the borders between the two kingdoms had not been well defined. What was of utmost importance in the rise to prominence of Santomera was the draining in the 18th century of more than 3,500 acres of land. A large number of landowners and several religious orders acquired a large part of the drained land and then stayed, to a large extent, closely bound to the places where they had their property and exercising their significant influence over them. Also at this time mining once again took on great importance. Both these facts led to a considerable population increase in this area.
In 1836 Santomera became a constitutional borough with its own Town Hall. The presence of the Dominican Fathers embodied the devotion to the Virgin of the Rosary and she in turn was devoted to the parish church which was built at the end of that century. Nowadays the inhabitants of Santomera are employed mainly in the service industries, in addition to agriculture and cattle breeding. The tourist who visits Santomera will be able to see the 19th century parish church, and the Bendame windmill of Arabic origin, which is to be found in the neighbouring village of Siscar. Further outstanding sights are the manor houses such as the one in Cobatillas which is an old Dominican convent from the 17th century. Among other places of interest are the reservoir of Santomera and the rambla salada (salty gulley) beauty spot, both with delightful scenery.
The Moors and Christians festival here has been declared of Regional Tourist Interest and will delight visitors with its colourful parades. The Rosary festival, which takes place on the 7th of October has a minstrel evening and a flamenco festival.