Royal wedding dress designer David Emanuel has opened an exhibition of traditional Welsh costumes at the National Library of Wales.
The Aberystwyth library said it was a "unique opportunity" to see a clothing collection dating from 1780.
A doll in Welsh costume given to a young Princess Victoria in Llangollen in 1832 will also be on show.
Mr Emanuel co-designed Princess Diana's wedding dress as well as clothes for her international visits.
The exhibition includes 12 examples of traditional Welsh costumes.
A collection of pictures by photographer John Thomas (1838-1905) will also be on show.
Among the surviving 4,000 glass plate negatives there are about 100 of women in Welsh costume dating from about 1870 to 1889.
A spokesman for the national library said it was "a unique opportunity" to see the library collection and private artefacts in a "comprehensive examination" of traditional Welsh costume since 1780.
"A Welsh lady's doll presented to Queen Victoria, on a visit to Wales, will return to Wales for the first time in 150 years," said the spokesman.
"The royal doll will be part of the traditional Welsh costume exhibition held in the National Library of Wales, Aberystwyth, over the summer months."
The wooden doll was presented to the then 13-year-old Princess Victoria at Llangollen in 1832 and is being loaned to the library by the Royal Collection.