In watching Downton Abbey, I was struck by the fact that the family members would have to wear their mourning clothes after their relatives had been lost on the Titanic. In this day and age, we wear black for a brief time to show respect but in Victorian times, the period of mourning was much longer and so would require a substantial wardrobe. By the Edwardian era, the length of mourning and the rules had eased up.
(On right: shown in the film "The Young Victoria", Victoria is in mourning after death of her uncle King William IV)
[Source] "In 19th century England, a widow was expected to remain in mourning for over two years. The rules were slightly less rigid for American women.
Many thanks to Evangeline of Edwardian Promenade for answering my inquiry of how mourning practices changed during the Edwardian era. She explains:
"Comparing two different editions of “Manners and Rules of Good Society”—one published in 1888 and the other in 1913—a widow in 1888 always wore mourning for two years; a widow in 1913 could wear mourning for two years, but she also had the option of only doing so for eighteen months. Crepe was also optional, with more widows choosing not to wear it by 1913. In 1888, jewelry was forbidden until eight months had past, whereas in 1913, barring gold, diamonds, could be worn after three months. Other periods of mourning (in-laws, cousins, etc) were drastically reduced in 1913 (i.e. Daughter-in-law or Son-in-law: 12 months in 1888, six months in 1913)."
Pics source: Metropolitan Museum of Art, Victoria & Albert Museum, Abiti Antichi