"The Pursuit of Diarmuid and Gráinne" (Irish: Tóraigheacht Dhiarmada agus Ghráinne or Tóraíocht Dhiarmada agus Ghráinne in modern spelling) is an Irish story found in many different versions. It is part of the Fianna Cycle of Irish mythology and tells the story of a love triangle involving the warrior Fionn mac Cumhaill, the princess Gráinne, and her lover, Diarmuid Ua Duibhne. All surviving texts are written in Modern Irish, and the oldest known version dates to the 16th century. However, some parts of the story may be even older, with origins tracing back to the 10th century.

The pursuit

The story begins with old Fionn, leader of the warrior group the Fianna, mourning the death of his wife, Maigneis. His men believe Gráinne, the daughter of High King Cormac mac Airt, is the most suitable woman for marriage, and plans are made for their wedding. However, at the betrothal feast, Gráinne is upset that Fionn is older than her father and becomes attracted to Fionn’s handsome warrior, Diarmuid (in some oral versions, this is because of a magical mark on Diarmuid’s forehead that makes him very appealing). Gráinne gives a sleeping potion to the other guests and tells Diarmuid to run away with her. At first, Diarmuid refuses because he is loyal to Fionn, but he agrees when she threatens him with a geis, forcing him to comply. They hide in a forest on the other side of the River Shannon, and Fionn quickly chases them. With help from other Fianna members and Aengus Óg, Diarmuid’s foster father, they avoid Fionn several times. Aengus Óg hides Gráinne in his invisible cloak while Diarmuid jumps over those chasing them.

Stories from Ireland and Scotland include different events, sending Diarmuid and Gráinne to various places. In many versions, Diarmuid initially refuses to sleep with Gráinne because he respects Fionn; in one story, she teases that the water splashing up her leg is more exciting than Diarmuid. A similar joke appears in some versions of the Tristan and Iseult story. Another part describes how Gráinne, who is pregnant, wants to eat rowan berries guarded by a one-eyed giant named Searbhán. At first, Searbhán is friendly, but he later refuses to give the berries. Diarmuid must fight him. Searbhán’s magic protects him from Diarmuid’s weapons, but Diarmuid finally wins by using the giant’s iron club against him.

Diarmuid's reconciliation and death

After many other adventures, Diarmuid's foster father, Aengus, helps Fionn and Diarmuid reach an agreement. The two lovers move to Keshcorran, County Sligo, where they have five children. In some stories, Fionn later marries Gráinne's sister. Later, Fionn plans a boar hunt near Benbulbin, and Diarmuid joins even though a prophecy warns that he will be killed by the boar. The boar wounds Diarmuid badly when he strikes it with a fatal blow. Fionn has the ability to save Diarmuid by letting him drink water from his hands, but he lets the water fall twice. Finally, Fionn's grandson, Oscar, threatens him with harm if he does not help Diarmuid. When Fionn returns for water the third time, it is too late—Diarmuid has already died.

Different versions of the story describe what happens to Gráinne afterward. In some, Aengus takes Diarmuid's body to Brú na Bóinne. In others, Gráinne vows to make her children seek revenge against Fionn for Diarmuid's death. In some versions, she mourns until she dies. In other versions, she makes peace with Fionn and helps him reconcile with her sons, or she even marries Fionn in the end.

Influence

The story of Diarmuid and Gráinne is well-known for its similarities to other love triangle tales in Irish and European stories. It shares similarities with the tale of Deirdre from the Ulster Cycle, where Deirdre is meant to marry an older man, King Conchobar mac Nessa, but instead runs away with her young lover, Naoise. After a long chase, Naoise is killed. Earlier versions of Diarmuid and Gráinne may not have been as similar to this story. For example, older records suggest that Gráinne married Fionn and later divorced him, rather than fleeing before their wedding. Another story, Scéla Cano meic Gartnáin, includes a scene where a young wife gives a drug to everyone in her household except her chosen lover. Like Gráinne, she persuades the unwilling hero to become her lover, leading to tragic outcomes.

Some scholars believe the story of Diarmuid and Gráinne influenced the legend of Tristan and Iseult, as noted by Gertrude Schoepperle in 1913. The Tristan and Iseult story began in France during the 12th century and is set in Britain. Tristan falls in love with the Irish princess Iseult while helping her travel to marry his uncle, King Mark of Cornwall. They begin a secret relationship, but after being discovered, their story includes events similar to Diarmuid and Gráinne, such as hiding in a secret forest.

In Ireland, many ancient stone structures, such as court cairns, dolmens, and wedge-shaped gallery graves, are called "Diarmuid and Gráinne's Bed" (Leaba Dhiarmada agus Ghráinne). These are believed to be places where the fleeing couple stayed overnight.