Sigurd (Old Norse: Sigurðr) or Siegfried (Middle High German: Sîvrit) is a legendary hero of Germanic mythology, who killed a dragon and was later murdered. It is possible he was inspired by one or more figures from the Frankish Merovingian dynasty, with Sigebert I being the most popular contender. Older scholarship sometimes connected him with Arminius, victor of the Battle of the Teutoburg Forest. He may also have a purely mythological origin. Sigurd's story is first attested on a series of carvings, including runestones from Sweden and stone crosses from the British Isles, dating from the eleventh century.
In both the Norse and continental Germanic tradition, Sigurd is portrayed as dying as the result of a quarrel between his wife (Gudrun/Kriemhild) and another woman, Brunhild, whom he has tricked into marrying the Burgundian king Gunnar/Gunther. His slaying of a dragon and possession of the hoard of the Nibelungen is also common to both traditions. In other respects, however, the two traditions appear to diverge. The most important works to feature Sigurd are the Nibelungenlied, the Völsunga saga, and the Poetic Edda. He also appears in numerous other works from both Germany and Scandinavia, including a series of medieval and early modern Scandinavian ballads.
Richard Wagner used the legends about Sigurd/Siegfried in his operas Siegfried and Götterdämmerung. Wagner relied heavily on the Norse tradition in creating his version of Siegfried. His depiction of the hero has influenced many subsequent depictions.
In the nineteenth and twentieth centuries, Siegfried became heavily associated with German nationalism.
The Thidrekssaga finishes its tale of Sigurd by saying
[E]veryone said that no man now living or ever after would be born who would be equal to him in strength, courage, and in all sorts of courtesy, as well as in boldness and generosity that he had above all men, and that his name would never perish in the German tongue, and the same was true with the Norsemen.
The names Sigurd and Siegfried do not share the same etymology. Both have the same first element, Proto-Germanic *sigi-, meaning victory. The second elements of the two names are different, however: in Siegfried, it is Proto-Germanic *-frið, meaning peace; in Sigurd, it is Proto-Germanic *-ward, meaning protection. Although they do not share the same second element, it is clear that surviving Scandinavian written sources held Siegfried to be the continental version of the name they called Sigurd.
The normal form of Siegfried in Middle High German is Sîvrit or Sîfrit, with the *sigi- element contracted. This form of the name had been common even outside of heroic poetry since the ninth century, though the form Sigevrit is also attested, along with the Middle Dutch Zegevrijt. In Early Modern German, the name develops to Seyfrid or Seufrid (spelled Sewfrid). The modern form Siegfried is not attested frequently until the seventeenth century, after which it becomes more common. In modern scholarship, the form Sigfrid is sometimes used.
The Old Norse name Sigurðr is contracted from an original *Sigvǫrðr, which in turn derives from an older *Sigi-warðuR. The Danish form Sivard also derives from this form originally. Hermann Reichert notes that the form of the root -vǫrðr instead of -varðr is only found in the name Sigurd, with other personal names instead using the form -varðr; he suggests that the form -vǫrðr may have had religious significance, whereas -varðr was purely non-religious in meaning.
There are competing theories as to which name is original. Names equivalent to Siegfried are first attested in Anglo-Saxon Kent in the seventh century and become frequent in Anglo-Saxon England in the ninth century. Jan-Dirk Müller argues that this late date of attestation means that it is possible that Sigurd more accurately represents the original name.Wolfgang Haubrichs suggests that the form Siegfried arose in the bilingual Frankish kingdom as a result of romance-language influence on an original name *Sigi-ward. According to the normal phonetic principles, the Germanic name would have become Romance-language *Sigevert, a form which could also represent a Romance-language form of Germanic Sigefred. He further notes that *Sigevert would be a plausible Romance-language form of the name Sigebert (see Origins) from which both names could have arisen. As a second possibility, Haubrichs considers the option that metathesis of the r in *Sigi-ward could have taken place in Anglo-Saxon England, where variation between -frith and -ferth is well documented.
Hermann Reichert, on the other hand, notes that Scandinavian figures who are attested in pre-twelfth-century German, English, and Irish sources as having names equivalent to Siegfried are systematically changed to forms equivalent to Sigurd in later Scandinavian sources. Forms equivalent to Sigurd, on the other hand, do not appear in pre-eleventh-century non-Scandinavian sources, and older Scandinavian sources sometimes call persons Sigfroðr Sigfreðr or Sigfrǫðr who are later called Sigurðr. He argues from this evidence that a form equivalent to Siegfried is the older form of Sigurd's name in Scandinavia as well.