With "Tannhäuser," Wagner entered upon the purely German themes which he was thenceforth to find so rich a mine. This story like many others was extremely old, yet it had been treated only rarely. Ludwig Tieck had written some verses upon it, and from these Wagner got his idea. Owen Meredith, the English poet, has also given us a charming version entitled "The Battle of the Bards." While Tannhäuser himself has been seldom written about, Walter von der Vogelweide—the minnesinger, and friend of Tannhäuser in the opera,—is the subject of many poems, one of the last being by Longfellow. Sir Walter is set down in German history as an actual person, and many things are told about his marvellous gift of song. Wolfram von Eschenbach—another historic character found in the operas—once wrote a famous old poem entitled "Parzival." Here Wagner discovered the germ of his beautiful story of "Lohengrin," following the lines of an old and well-nigh forgotten legend. The opera of "Parsifal" though not completed till more than thirty years later was also conceived at this time, and remained a cherished project. Legends of the Holy Grail, with which it deals, are familiar in every Christian country. There is much in the characters of both Parsifal and Lohengrin to remind us of Tennyson’s Sir Galahad, in "Idylls of the King," which treats of the Holy Grail. In "Tristan and Isolde" we have another legend which was well known during the Middle Ages. It was known in Wales, Ireland, Brittany and Germany where it was a frequent theme with minnesingers, or wandering minstrels, like Walter von der Vogelweide. One of the earliest German authors to write down a version of it was a certain Godfried of Strasburg; and Wagner had at his command this and numerous other versions. English poets, also, have been greatly attracted by the tale. Sir Walter Scott, in "Thomas the Rhymer," told the simplest version. Matthew Arnold, Tennyson, and Swinburne have given notable poems of some length on the subject. During the Middle Ages, and particularly in the thirteenth century, the city of Nuremberg was the seat of a famous musical guild, or training-school for poets and singers. In his "Master Singers," Wagner has followed history for his scene, characters and traditions, though he has made droll use of them. The Master Singers have left substantial proof that they really lived. There are poems still in existence, signed by Sixtus Beckmesser, Veit Pogner and others; while Hans Sachs has left whole volumes behind, and his memory is so revered that he is looked upon almost as the patron saint of his city. Longfellow says in his poem on "Nuremberg": "Here Hans Sachs, the cobbler-poet, laureate of the gentle craft, Wisest of the Twelve Wise Masters in huge folios sang and laughed!" Wagner also obtained his idea for the contest of song from one of Hoffmann’s novels entitled "Sängerkrieg." He made use of the same idea in "Tannhäuser."