This is a rare memorial ring for a decorated commander of the Royal Navy, James Haldane Tait.
Given the inscription, design, and the inclusion of a lock of hair braided behind a window on the inside of the band, this ring would have been made after his passing for a close family member. Given the feminine design and that Tait had only a son, it's likely this belonged to his widow Marion Yule.
The Victorian Era saw a boom in the popularity of memorial jewelry, particularly for pieces which included a lock of hair. Even Queen Victoria lost Prince Albert, in 1861, pieces like this were high fashion.
Along with the other rituals of mourning including clothing and strict etiquette, mourning jewelry was a permanent reminder of the loved one, and rings particularly allowed the wearer to keep their memory literally at hand. Memorial jewelry could be an opulent and one of the few outward signs of grief, when in somber black an upper class lady could wear a beautifully made piece like this ring to show her deep love for the person lost. To the Victorians hair had a second meaning, a reference to immortality. Because hair does not decay it was seen as an incorruptible piece of the person lost.
