BSOAF

damian Name Meaning and History
French, Spanish (Damián), Italian (Venice), Czech and Slovak (Damián), and Polish: from the medieval personal name Damian, Greek Damianos (from damazein ‘to subdue’). St. Damian was an early Christian saint martyred in Cilicia in ad 303 under the emperor Domitian, together with his brother Cosmas. In some accounts the brothers are said to have been doctors, and together they were regarded as the patrons of physicians and apothecaries. A later St. Damian lived in the 7th–8th centuries and was bishop of Pavia; he may have had some influence on the popularity of the personal name in Italy.
Americanized spelling of Hungarian Damján or Damján or Slovenian Damjan, Damijan, cognates with 1.
Jewish (from Poland): either an ornamental adoption of the Polish personal name Damian as a surname, or a habitational name from the village of Damiany in northeastern Poland.

Lots of times someone in the history of the family just picked a last name....some became popular in different areas, thus you have american names, dutch, french, hispanis and so on and so forth. It doesn't really matter. I have a weird last name.