Wikipedia
Greysteil ("Graysteel") was a medieval poem popular in 16th century Scotland, set to music and performed for James IV of Scotland and James V of Scotland. The poem was also called Syr Egeir and Syr Gryme, Eger and Grime, the names of the two knights who fight Greysteil and whose contrasted virtues are the poem's real subject. The name of the protagonist, a strong and agile knight, opulent, tainted with the black-arts, and vanquished by a magic sword provided by a powerful woman, was adopted as a nickname for two 16th-century courtiers, Archibald Douglas of Kilspindie who was said to have been dominated by his wife Isobel Hoppar, and William Ruthven, 1st Earl of Gowrie, and Alexander Montgomery, 6th Earl of Eglinton in the 17th-century, and was a given name of the 20th-century 2nd earl of Gowrie.