Of all of the female characters in the Four Branches, it is only Arianrhod who maintains her personal power and autonomy throughout the narrative; indeed, if there are remnants of past social orders to be found in the tales of Y Mabinogi, it is most strongly evidenced in the Fourth Branch, especially as it concerns Arianrhod in whom we see a woman in complete control over her life and her destiny.
Dwelling on an island fortress set apart from the rest of Gwynedd, she is ruler of her own court and lives by her own rules. Not only do we see Arianrhod buck convention with her rejection of the role of motherhood, but we see her go unpunished for her unorthodox behavior. According to scholars, it is this rejection of the roles of wife and mother that allow Arianrhod to continue to operate with the power and privileges of a single woman.37 We see her competently performing the duties of a lord: she is concerned with the well-being of her people, is well-versed in courtly behavior, and is clearly well-educated. When Gwydion and Lleu visit her realm in disguise, she is shown receiving them warmly, telling stories and conversing easily with Gwydion, her brother, who is oft-praised for the excellence of his bardic abilities. “This may be the most attractive vision we have of the stubborn daughter of Don: the welcoming hostess who attracts the interest of her male guests with ymdidan (conversation) about their favorite subjects.” 38
These circumstances would have been unusual for medieval Welsh women and may have been a narrative survival from a different time, perhaps originating in pre-Christian Celtic Britain and preserved in orality before being written down. It is a general contrivance of myth and legend that they tend to reflect the sociocultural context which birthed the tale, and when it does not, it may reflect on an older order. We do know that pre-Christian Celtic women enjoyed more autonomy, rights, and privileges than their medieval peers, so—as with the matrilineal inheritance paradigm which seems to feature in the Fourth Branch—a woman who rules in her own right and appears to answer to no man may be a reflection of that earlier cultural norm, and may have been preserved and included in the Fourth Branch as part of depicting Arianrhod as Other.
Arianrhod’s Otherworldly status is not explicit in the narrative, aside from her heritage as the daughter of Dôn, the Divine Ancestress of a powerful lineage—a lineage which includes Arianrhod’s magic-using uncle Math and brother Gwydion. It is worthy of note that the land Arianrhod rules over is named after her, a convention which scholars associate with “powerful goddesses who give their names to the lands with which they are connected.” 39 Perhaps then, this, more than anything, marks Arianrhod as a representative of Sovereignty as often these are tutelary divinities, like Eriu, goddess of Ireland.
Most directly, Arianrhod’s claiming of Mother Right, and the struggle of Gwydion against it, is an extension of the subversion we’ve seen throughout the Fourth Branch. It is also significant to note that, regardless of Math’s kingship and the magical abilities possessed by both he and Gwydion, they are powerless to break the destinies lain by Arianrhod upon her son. The most these powerful men can do is to find a way around Arianrhod’s pronouncements.
Symbolically, Arianrhod may be seen as an initiator, the Terrible Mother archetype who sets up challenges before her son, the Solar Hero, through which he earns his manhood/kingship and/or comes to actualize his godhood. As the daughter of Dôn and Beli, both of whom have analogues in Irish myth as the divinities Danu and Bel, it is likely that Arianrhod was also originally divine. Her name means “Silver Wheel,” which is very suggestive of the moon and its phases. This lunar motif, coupled with a wheel’s symbolic connection to the turning seasons, as well as Arianrhod’s laying of destinies throughout the Fourth Branch, makes a strong argument for considering her a personification of fate. Furthermore, this kind of testing of a potential king is a classic hallmark of a sovereignty goddess.