While it was known that medieval men wore undergarments like modern-day shorts, it was thought that women simply wore a chemise.
Bras were thought to be a modern invention, appearing just around 100 years ago, whereas Knickers were believed to have made an appearance only in the late 18th century.
Four bras and two pairs of pants were among almost 3,000 fragments of clothing and other detritus found in Lengberg Castle in East Tyrol during recent renovations, BBC history magazine reported.
Two of the bras resemble modern counterparts but the others are described rather bluntly as 'shirts with bags'.
The knickers are similar to the string bikini briefs in fashion today, while the bra is like that of its modern-day counterparts, featuring fitted cups and delicate straps.
They had remained hidden in a vault beneath the floorboards of an Austrian castle since the 15th century.
It is thought that they were buried when the building was extended in 1480 and that the exceptionally dry conditions stopped the fragile garments from disintegrating over the centuries, the report said.
"Nothing like this has ever come up before," Hilary Davidson, fashion curator at the Museum of London, was quoted as saying by the 'Daily Mail'.
She added that the discovery "totally rewrites" fashion history.
"These finds are a very exciting insight into the way people dressed in the Middle Ages," she continued.
Beatrix Nutz from Innsbruck University confirmed the find after radiocarbon-dating tests.
