Isolde is from the Old High German *Iswalda* — īs (ice) + walt (rule). **The Irish princess heroine of the medieval romance *Tristan and Isolde* — betrothed to her uncle King Mark of Cornwall, but drinking a magic love potion with the knight Tristan en route to her wedding, she and Tristan fall into a hopeless and adulterous love that ends in their deaths**. **One of the foundational stories of European romance, with Arthurian connections** — Tristan's roundtable knighthood appears in Malory. **Wagner's opera *Tristan und Isolde* (1865) reinvented Western music** with its dissonant Tristan chord — among the most influential pieces of the 19th century.
Subject of Joseph Bédier's *The Romance of Tristan and Iseult* (1900) and Wagner's opera.
Isolde reduces to one — the number of Tristan's lover.