During the German occupation of Czechoslovakia during the Second World War, Borkovský was forced to withdraw a book he had published identifying early Slavic influence in the region.

After the end of the war and with Prague under Soviet occupation Borkovský published a paper retracting this earlier work and identifying IIIN199 as a nobleman of the Přemyslid dynasty.

The skeleton was discovered in the third courtyard of Prague Castle on 11 July 1928 by Ukrainian-born archaeologist Ivan Borkovský, who was leading a National Museum excavation project.

[1][2][3] The project was investigating a burial ground thought to be associated with an early hill fort on the site of Prague Castle dating to AD 800–1000.

Borkovský was more prominent by the 1930s but was keen to keep a low profile on the potentially controversial matter of ethnic identification of the burial as he was seeking to obtain Czechoslovak nationality.

[1][2] Two knives were located near the body's left hand, and at the right elbow an object was found that could have been either a razor or a fire steel, which would have been an important status symbol.

After explaining he had been forced to write the pro-Nazi paper, he published a second article on the skeleton in 1946 that identified the subject as a noble of the early Přemyslid dynasty.

[3] Reassessment of the identification of IIIN199 was not possible during the Cold War due to the political ramifications, though anthropologist Emanuel Vlček published a paper in the 1970s that claimed the burial must be later in the 9th century and not related to the Přemyslids.

Analysis of the strontium isotopes in the skeleton's teeth has shown that he grew up in Northern Europe, likely on the southern Baltic coast or in Denmark.

[2] Jan Frolik of the Czech Academy of Sciences has suggested that the individual came to Prague as a young man to serve the early dukes of Bohemia (either Bořivoj I or Spytihněv I).

[3] The conflicting assessments of IIIN199 have been described as reflecting "the fate of Czechoslovakia and Central Europe, as the burial became entangled with Czech identity, Nazi occupation and the manipulation of archaeology".