Lohengrin (opera)
The second time that the Herald calls the unknown knight, a miracle happens. A boat, pulled by a swan, appears.  A knight in shining armour stands in the boat.  He gets out of the boat, tells the swan that it can go, and then he greets the king.  He asks Elsa if he can be her knight.  Elsa kneels in front of him and asks for his help.  He says that he will serve her, but he asks one thing: that she should never ask him what his name is or where he comes from.  Elsa agrees.  Everyone, except for Ortrud, prays and the fight starts.  The unknown knight wins, but then he spares Telramund’s life.  The unknown knight now takes Elsa’s hand and asks her to marry him.