|Ethnicity||Erin, Fair Folk, Sea People|
|Siblings||Willow and hundreds of others.|
|Children||Firinne and Ronan (twins)|
|Significant Other||Clodagh (wife)|
Cathal is part human and part fey, his mother Firinne being a human descended from the Sea People, and his father, Mac Dara, a prince of the Tuatha de Dannan.
Cathal was born after his mother, Firinne, was seduced and impregnated by Mac Dara, a Prince of the Fair Folk. Firinne loved her son and realised that after seven years had passed, Mac Dara would return for Cathal, and so she brought Cathal to Lord Murtagh and asked that he be raised in Murtagh's household. Murtagh agreed willingly, but when he offered to accomodate her as well she refused.
Cathal grew up in Whiteshore, in the household of Lord Murtagh. He and Aidan, Murtagh's son, developed a close friendship, and they were like brothers. Cathal never understood his mother's decision to stay away from him, and thought that she didn't love him. When Cathal was seven, he and Aidan found Firinne's body floating in a stream, and it was believed that she committed suicide. Cathal came to believe that she wasted away out of love for the man who abandoned her, and finally killed herself when she could no longer bear it.
When Cathal was nine years old, Lord Murtagh gave him a dog as a gift. Aidan, jealous at his father's attention on a bastard-born commoner, kicked the dog so brutally that it died.
As Cathal grew up he felt as if someone were trying to draw him away from safety, so he made his own 'protection'. He gathered small trinkets that meant something to him and sewed them into a cloak. Because Cathal was half-fey, his cloak of trinkets became a source of protection for him from Mac Dara and the Fair Folk who wished him ill. It was because of this that Mac Dara was unable to find him for so long. However, when Cathal was twelve years old Mac Dara did locate him, and placed a geis on him which would trap him in the Otherworld should he ever return there, thus forcing him into the role Mac Dara intended for him.
When Aidan was offered a place on Inis Eala as one of Johnny's men, Cathal went with him. On the island he was protected from Mac Dara's reach, as long as he stayed there, and so he was safe. When Johnny intended for him to accompany his party to Sevenwaters for Deirdre's wedding, Cathal argued against it, but was overruled.
Heir to SevenwatersEdit
Seer of SevenwatersEdit
Four years after the events of Heir to Sevenwaters, Clodagh is pregnant with her and Cathal's first child. This makes Cathal even more protective of her, and worried about the length and power of Mac Dara's reach. Cathal hopes for a girl, so that Mac Dara will not target her, but senses that they will have a boy. He begins to practise his magic again, so that he will be able to fight Mac Dara and protect his family from him should that time ever come.
After a shipwreck occurs near the coast of Inis Eala, Cathal feels guilt at not being able to leave the island and save the people on board using his magic and berates himself about it. He begins to have nightmares which disturb both his sleep and Clodagh's, causing Clodagh to worry about him. Cathal is also afraid that the shipwreck was supernaturally caused by Mac Dara, in an attempt to draw him away from Inis Eala. After Sibeal saves an amnesiac man from drowning, rumours arise about the 'ill-luck man' and point toward him being the cause of a sudden increase in unlucky incidents on the island. Cathal becomes even more worried because of this, and becomes convinced that the man, who Sibeal has called Ardal, may be a spy for his father. He confronts him quietly about this, demanding to know the truth, but the man can tell him nothing.
Flame of SevenwatersEdit
When Cathal and Clodagh receive Ciaran's message through Deirdre, Cathal is compelled to leave Inis Eala and aid Ciaran in defeating his father. Clodagh insists that she and their children accompany him, resulting in a painful argument that Clodagh wins. Together Cathal and his family leave the island and meet Ciaran near a cluster of standing stones, where Cathal embraces his children and farewells Clodagh for which he believes will be the last time.
Cathal and Ciaran walk to the cottage where Willow lives, and wait for her to appear. When she does, Willow gives them the final verse of the geis, and warns them that Mac Dara has a dangerous rival who will challenge him on the morrow who also knows the geis, and that they should hurry to get to the conclave before it happens. Ciaran and Cathal fly to the conclave as crows and arrive in time to apprehend Caisin Silverhair and Mac Dara. Cathal intends to take over as Prince of the Otherworld, but Ciaran instead chooses to take his place, knowing that Cathal has a wife and children waiting for him in the human world. Cathal is shocked at this, and is further shocked and troubled by his father's death, for despite Mac Dara's cruelty and evil will, he was Cathal's father and did love his son in his own twisted way.
Cathal is formally introduced to Maeve, who he remarks is 'very like Clodagh', from her astounding generosity to her bravery. Together with Finbar, Artagan, Tiernan and Daigh, they leave the Otherworld behind them and return to the human world. Cathal is reunited with Clodagh, Firinne and Ronan. Though he is overjoyed at having returned to them, Maeve narrates that it will take him a long time to come to terms with his father's death.
Cathal and Clodagh decide to split their life between Sevenwaters and Inis Eala, so that Finbar will have company as he grows up.
Cathal uncannily resembles his father, something which causes many problems and confusion in Heir to Sevenwaters. He has a fox marking around the corners of his eyes and nose, marking him as a member of Johnny's band. He has dark hair and eyes and pale skin.