From the experts:
Like Verity and Amity, this inclusive virtue name used by the colorful British literary Mitford family is ready to join its more popular peers Hope, Faith, and Grace.
The name was embraced by the Puritans in the seventeenth century, but was not as common as others. In literature it occurs as a servant in Thomas Hardy's A Pair of Blue Eyes.
Unity Valkyrie Mitford supposedly inspired the character of Bellatrix Lestrange in J. K. Rowling's Harry Potter series. Unity Kincaid is a character In the Sandman series by Neil Gaiman.