The surname O'Shanahan is originally a name that appeared in Gaelic as O Seanachain, which is derived from the word "sean," meaning "old."
from very ancient times.
This web page shows only a small excerpt of our O'Shanahan research.Another 409 words (29 lines of text) covering the years 1318, 1802, 1863, and 1877 are included under the topic Early O'Shanahan History in all our PDF Extended History products and printed products wherever possible.
Scribes and church officials, lacking today's standardized spelling rules, recorded names by how they were pronounced. This imprecise guide often led to the misleading result of one person's name being recorded under several different spellings. Numerous spelling variations
of the surname O'Shanahan are preserved in documents of the family history. The various spellings of the name that were found include Shanahan, O'Shanahan, Shahan, Shannon, Gilshenan and many more.