"the miniature portrait of her father"
Miniature of George Washington (1800)
Public DomainMiniature of George Washington (1800) - Credit: Robert Field

Portrait miniatures were very popular in Europe from the 16th century through to the 18th century.  Portraits of family members had obvious sentimental value. Soldiers and sailors would often carry miniatures of their loved ones while travelling.  Miniatures were also useful as a means of introduction: a nobleman proposing the marriage of his daughter might send her miniature portrait to potential suitors for their appraisal.

The first miniaturists used watercolour to paint on stretched vellum.  During the second half of the 17th century, enamel painted on copper became popular. In the 18th century, watercolour miniatures were painted on ivory. Some were as small as 40mm × 30mm, and they were often used in jewelry or on snuff box covers.  From the mid-19th century, the development of daguerreotypes and photography rendered miniatures increasingly obsolete.