The Story of Tristan and Isolde:
Many medieval poems and surviving prose texts relate the adventures of the heroic knight, Tristan and his ill-fated love for the beautiful Irish princess Isolde.
Our story is taken from the tale by Marie de France written around 1160, entitled "Lai du chevrefoil" (The tale of the honeysuckle). Tristan was the nephew of King Mark of Cornwall and heir to the throne. Upon returning from a trip to Ireland, Tristan tells King Mark of the beautiful princess, Isolde, daughter of the Queen of the Green Isle. King Mark decides to appease his barons who insist upon his producing a true heir to the throne, for they were jealous of Tristan. The King sends Tristan back to Ireland with a proposal of marriage to Isolde. However, the Irish countryside is being ravaged by a horrible beast. In desperation, the Irish Queen has decreed that who ever slays this beast will win the hand of her daughter, Isolde. Tristan slays the beast and declares his intention to bring Isolde to Cornwall for King Mark. It is agreed. The Irish Queen, concerned for her daughter's happiness in marrying a much older man, has a love potion made for the married couple to drink upon their wedding night in order to ensure their happiness. The potion is entrusted to Isolde's handmaiden, Brengwain.
On the sea journey from Ireland to Cornwall, Tristan becomes thirsty and Brengwain accidentally gives both Tristan and Isolde the vial of love potion to drink. From this point on an uncontrollable passion develops between the two lovers. But Tristan, knowing that their true desires of living happily ever after are not to be, performs his duty by delivering Isolde to Cornwall and presenting her to King Mark. The King and Isolde are wed, but Tristan and Isolde continue their love affair until King Mark becomes convinced that his most trusted knight and his queen are meeting secretly. Tristan is banished. Here is where the story of "Chevrefoil" begins.
(from Chevrefoil liner notes)