A replica of the crown, which was supposedly worn by medieval Bulgarian rulers, was presented in the National History Museum (NIM) in Sofia on Tuesday.

The replica portrays the crown which was supposedly manufactured in the Vatican and presented as a gift by Pope Innocent III to Tsar Kaloyan in 1204.

This crown, which supposedly had a weight of 1.5 kilogrammes and was made of pure gold and more than 700 pearls, was then worn by all Bulgarian rulers until the fall of country under Ottoman rule at the end of the 14th century.

The fate of the original crowns worn by Bulgarian rulers is unknown as none of them has survived to the present.

The crown worn by the rulers of the First Bulgarian Empire was captured in the then capital Preslav when the city fell to the Byzantine armies in 971.

The crown was taken to Constantinople, but its tracks are lost there, with the same fate befalling the crowns worn by later rulers.

The replica was crafted by three jewellers with gold, pearls and precious stones collected as donations.

The crown is based on the fresco depicting the image of Tsar Konstantin Tih and his spouse Irene in the Boyana church and other frescos in the Bachkovo monastery.

In order to choose an average size, the crown was tried on several male heads.

A wax casting was made first, with the bottom part of the crown proving most difficult to manufacture.

A replica of the female crown is expected to be ready by the end of April next year.

The crown will remain on display in the museum, which offers free admission to its visitors on Wednesday.