While most couples celebrate Valentine's Day with flowers, chocolates and candlelit dinners, archivists have unearthed evidence that a less savoury romantic gesture was practised historically - bestowing a severed head on a loved one.
This left-field approach to love-making, practised by 19th-century Taiwanese aborigines, was discovered in the 150-year-old letters of botanical explorers.
Taking someone's head after killing them was a ritualistic part of life in the culture until the 1930s and suitors would present severed heads to potential partners to woo them or to brides to celebrate their marriage, according to archive material in the Royal Botanic Gardens at Kew.
The ritual, highlighted as part of the Archive Awareness Campaign, is revealed in a letter to Kew written in 1864 by Kew gardener Richard Oldham, who explains why he cannot explore the Taiwanese mountains near Tamsui.
He wrote: "As the spring is the season at which the young savages marry, it is yet unsafe to go as they always fight either with other savages, or other Chinamen in order to get heads with which to celebrate their marriages, and it is possible they might take a particular liking for the heads of foreigners. It will perhaps be safer to go in the summer."
In 1903, author, explorer and consul James Davidson recorded that a northern tribe called the Atayals were the most active head-hunters and used severed heads to gain favour with unmarried women.
They were also used to obtain rank and were thought to bring luck and protection, his correspondence reveals.
The heads themselves were said to have been kept in the open air on a narrow platform and never removed.
Kiri Ross-Jones from the Royal Botanic Gardens said: "As Valentine's Day approaches, we can be glad that our romantic rituals are likely to be more idyllic and involve displays of flowers and candles than dismembered heads."