An opera in three acts, written and composed by Richard Wagner and dedicated to his friend, Frans Liszt. It was first produced in 1850 in Weimar, Germany, and later published in 1852. Wagner himself didn't actually hear his own creation until 1861 due to being exiled for his participation in an uprising. Lohengrin was initially very poorly received.

Act I begins in the land of Brabant, where civil strife has torn apart the countryside. A Herald announces the arrival of King Heinrich, who asks Count Friedrich von Telramund, the stand-in ruler of the province, to explain what the turmoil is about. Telramund explains that one of his wards, Gottfried, the heir of Brabant, has disappeared, and that Elsa, Gottfried's sister, is behind it. Telramund accuses Elsa of colluding with a secret lover to murder Gottfried, and have her lover take his place as the heir. His accusation is at the root of the local turmoil, as roughly half of the local populace sides with Telramund (the Brabants), while the other half side with Elsa (the Saxons). The King calls Elsa out, expecting to get an explanation. Instead, Elsa is distant, speaking of a knight in shining armor. The King decides that the matter must be decided with a duel between Telramund and Elsa's mystery knight. The Herald calls out for the knight, but no one answers. Elsa begins praying fervently, and suddenly her knight appears in a boat drawn by a swan. He offers to marry Elsa and aid her against Telramund, but only on the condition that she never ask his name or place of origin. She agrees, and the knight declares his love for her. He and Telramund duel, the Count is defeated, and the populace is ecstatic about finally having a resolution to the conflict.

In Act II, Telramund and his wife, Ortrud, swear vengeance against the knight and his new wife. Elsa appears, innocent of their plotting, and offers Ortrud friendship as Telramund sneaks away to enlist the help of four nobles against the knight. Meanwhile, everyone prepares for the wedding, and the Herald announces that the knight will lead the Brabantines into battle against the Huns. As Elsa and Ortrud prepare for the wedding, Otrud turns on her new friend, declaring her fiance to be an imposter. The King and the knight arrive, both alarmed at Ortrud's presence. The knight comforts Elsa, but is then forced to deal with the arrival of Telramund, who accuses the knight of using sorcery to win the duel. He demands to know the knights name, but he refuses, telling Telramund that only one person can ask him that question. Telramund turns to Elsa, trying to convince her to ask the knight about his name and origins. She is shaken, but in the end she and the knight leave for the wedding.

Finally, in Act III, the knight and Elsa are wed, and the newly married couple proclaim their love for each other. Elsa's anxiety gets the better of her, and she asks the knight his name. Just then, Telramund attempts to assassinate the knight. Elsa hands the knight his sword, and he slays Telramund. The knight sends Telramund's body to the king, and tells Elsa he will reveal his name to everyone. With the king and the local populace present, the knight proceeds to reveal that he is Lohengrin, a Knight of the Holy Grail, sent by his father, King Parsifal, to defend Elsa. However, now that he has revealed his identity, he must return to his home. The swan arrives to take Lohengrin home, but before he goes, he leaves Elsa his sword, horn, and ring. Ortrud bursts in, enraged at the death of her husband. She reveals that it was she who made Gottfried disappear, using the power of the Old Gods to magically turn him into a swan. Lohengrin begins praying, Ortrud is swept away, and the swan is transformed back into Gottfried, Elsa's brother and heir to Brabant. Lohengrin vanishes, and Elsa falls to the ground, lifeless.

This opera is a monster, clocking in at about 4 and a half hours long. The opera is known for having an especially large chorus, in fact the largest opera chorus period. It should come as no surprise then that the best music in Lohengrin is the choral work, such as the Seht chorus in Act I during Lohengrin's arrival and the victory chorus after he defeats Telramund. This opera is also the source of the wedding march, performed at the beginning of Act III.