Honor
The key theme of the Tain is honor, and the importance of possessing it. Within this theme we also see the consequence of being without honor. The Queen brokers a deal to borrow the prize bull, and the owner of the bull, who has honor, keeps the agreement and therefore peace is maintained. However when the Queen's messengers let slip that she would have stolen the bill if the owner had not agreed to lend him to her, her lack of honor is revealed and war ensues. She also acts without honor when she opts to invade Ulster to take the bull from his rightful owner.
Cu Chulainn has a great deal of honor and courage. He respectfully agrees to yield to his foster father if Fergus agrees to yield to him at their next meeting. As a man of honor Fergus does this and this results in the invading army having to retreat, showing again that honor creates positive results. The Queen, having no honor, steals back the bull but he then kills her husband's prize bull, and dies himself, proving that her lack of honor had caused them to lose both stud animals and end up with far less than they started the invasion with.
Mystical Figures
As with all early literature, legends are peppered with mystical characters who live among human characters and are wholly accepted. The mystical characters often have mystical abilities and in this particular text the mystical figures are able to metamorphose into other creatures. They also affect the outcome of different situations. The mystical figures occur more in pre-Christian writings and folklore before the advent of a more structured church.
Political Instability
The political situation is very volatile and this is one of the themes of this work. Invasions took place easily and did not have to be precipitated by anything particularly serious. The answer to any form of failed negotiation was invasion and in this case the precipitating factor seems to be the Queen wanting her own way. The theme also demonstrates how families could be on opposing sides in a battle because they live on different sides of a border and this is still a theme that is current today.
