This is the Ur-text of the Tristran and Isolde legend – or, as in this story, Tristran and Ysolt. Only a fragment of the whole poem is extant, but the rest of the story is known from the later Norse and German translations/adaptations. It is author of the German version, Gottfried von Strassburg, who identifies the author as “Thomas of Britain”. Apart from that, all the evidence about the author having any links with England is circumstantial: there is of course the setting, partly in England, and the poem is written in Old French, with a smattering of Anglo-Norman forms. So the poem could conceivably be connected with the French-speaking court of Henry II. And who knows, maybe his name was really Thomas? He probably used some other source text, God knows in what language, which is now lost. The poem is written in rhyming couplets, but the translation in the NAEL is unfortunately in prose.
The excerpt printed here is the big operatic finale of the lovers’ death. Tristran is languishing from a poisoned wound and he sent his brother-in-law Caerdin to fetch Ysolt. Ysolt escapes with her maid Brengvein at night, makes her way to a ship and sails off to Normandy. Meanwhile Tristran is wrecked not only by the physical pain, but also by doubt: will Caerdin make it? will Ysolt be faithful to him? He asked Caerdin famously to signal with the colour of the sail whether he is bringing Ysolt with him. He at some point asked to be carried to the shore, but decided that he can’t stand seeing the sail of the bad news himself, so he asks to be carried back home.