The porter, or seneschal, or gatekeeper, is one of the least understood offices among the Celts.
The gatekeeper had to be an established warrior, a man whose successes gave selectees instant credibility. Wit, strength, and athleticism were all good qualities to have.
The porter's main function was the screening of young men requesting to serve the king. His job was to make certain they met a standard. There are few mentions of exactly how the process went, but it seems a safe assumption that a certain size and bulk were required before testing, and that the gatekeeper's evaluation might involve physical, mental, or a combination of both aspects. Successful candidates would be introduced to the king and sat at the far end of the table. Rejects would be sent home.