A chieftain of the Scottish Highlands, the Chief of Ulva's isle, has turned up at Lochgyle with Lord Ullin's daughter, the young lady with whom he's eloped.
It's fair to say that Lord Ullin's not exactly thrilled with this state of affairs. In fact, he's so infuriated with his daughter's elopement that he's sent three of his best horseman after her and her beau. As the young man tells the boatman, if these men catch up to the young couple, then his blood, the chieftain's blood, will stain the heather.
With the irate aristocrat's men in hot pursuit, it's absolutely essential that the chieftain and Lord Ullin's daughter are able to cross Lochgyle. With that in mind, the young chieftain promises to give the boatman a silver pound if he'll row them across the loch.
Upon hearing this, the boatman can't quite believe his ears. Who on earth would want to make such a treacherous journey? Naturally, the boatman wants to know who would make such a dangerous and unusual request:
Now who be ye would cross Lochgyle,
This dark and stormy water?
It is then that the chieftain introduces himself and his female companion as, respectively, the chief of Ulva's isle and Lord Ullin's daughter. The boatman agrees to transport them across the loch but not because he's been offered silver. He's doing it for the “winsome lady,” Lord Ullin's daughter.