collection, making off in a motorboat after the heist.
Two crowns - one belonging to King Karl IX, the other to Queen Kristina - were snatched on Tuesday morning, as well as a royal orb.
The jewels were stored in the cathedral in the town of Strängnäs.
Eyewitness Tom Rowsell told NBC News' Swedish partner Aftonbladet that he saw two men jump into a "little white boat".
The motorboat is described as small and open, though its color is now unclear.
The crown jewels of Charles IX and his wife Christina were buried with them upon their deaths in 1611 and 1625 respectively.
'We have some different information about how exactly the boat looked.
"I knew immediately they were burglars, because of the way they were behaving", he added. But all those displays, in addition to catching the eyes of thousands of visitors, seem to also have caught the attention of a number of thieves.
"'It's 1-0 to them right now", a police spokesperson said, according to The Express.
An official with the Swedish police's National Operations Department told a local media outlet that she thought the stolen goods would be "impossible to sell" due to how unique and recognizable they were.
Police quickly mobilised and pursued the thieves by sea, on land, in helicopters and planes.
Christofer Lundgren, dean of the cathedral, said: 'This is part of the national cultural heritage - this is a theft from Swedish society'. Back in 2012, a friend of the family attempted to steal some of their pieces amounting to more than USD$120,000.