The etimological origin of the name is arabic. It is: "Al Quantara" (you will find a city called this way in the north side of Egypt, at the Nile delta), and in fact it means "The Bridge".
There could be several different origins of our name: - Arabic, like I explained above, from the arabic conquest of the Iberian Peninsula, in 711. - The Chivalry Order of Alcantara. It was a medieval military order fighting against the moors in central Spain. They eventully be successful to siege and take the village of Alcantara (Extremadura, Central-western Spain, near the Portuguese border) and the Order took the name of the village. More info: http://www.newadvent.org/cathen/01271b.htmhttp://www.newadvent.org/cathen/01271b.htm - Jew. In the XVI century the hebrews were forced to convert to cristianism or leave Spain. Some of them go away, but other stay here and took family names from different origins: colors, flowers, crafts, and the name of their villages.
Some small facts: - The correct writing of the name is Alcántara (in Spanish). I think it is written without accent in Portugal. - There are lots of towns in Spain called "Alcántara". - Brazil got an emperor during XVIII century (if I am not wrong) and his name was Pedro de Alcantara. The family name spreaded both in Spain and Portugal. - Lots of Spanish conquerors of America had our family name. - There is a place in Sicily called Alcantara. It seems to be a kind of small canyon. It is not extrange because of the south of Italy was under Spanish rule during two centuries. - There are more than a bridge in Spain called "Puente de Alcántara" (which is in fact a redundace, because "Puente" means also "Bridge"). See: http://www.geocities.com/Heartland/Estates/4058/http://www.geocities.com/Heartland/Estates/4058/ - The arms of our familly are a silver sky with a bridge over a river, among the two green sides, and an small tower in the middle of the bridge. - If you are interested to know more about the village of Alcántara, you can visit the address: http://www.ayto-alcantara.es/http://www.ayto-alcantara.es/ (it seems not to work at this moment). It is the web site of the Town Hall of Alcántara.