Queen Victoria was queen of the United Kingdom of Great Britain and Ireland from 1837 until her death in 1901; for the last thirty years of her reign she held the additional title of Empress of India. One of the longest-serving monarchs in history, her sixty-three year rule oversaw a period of expansion and prosperity for the British Empire. After the death of her husband, Prince Albert, in 1861 she only wore black, as a sign of mourning. A good portion Sherlock Holmes' canon adventures occurred during her illustrious reign.
Sherlock Holmes, in a fit of boredom, uses the wall of his sitting-room for target practice, shooting the "patriotic" letters V.R. (for "Victoria Regina", eg. Queen Victoria) into the wall with a pistol.
After successfully recovering the stolen plans from Hugo Oberstein and arranging his arrest, Holmes travels to Windsor. He returns with an exceptionally fine emerald tie-pin, which he explains was a gift from a "certain gracious lady" for protecting her interests. Though Holmes never reveals her name, Watson imagines he knows who she was and the reader may guess the woman was none other than the Queen.
In this story, an unnamed detective (at the end implied to be James Moriarty), and his assistant, S. M., are tasked with investigating the murder of Prince Franz Drago of Bohemia, a nephew of Queen Victoria. It is slowly revealed that "Royalty" are Lovecraftian horrors that conquered humanity seven hundred years previously, split between the inhuman Old Ones, like Victoria, and half-breeds like Franz Drago, who are the spawn of the Old Ones and humans. The Queen's name, Victoria Gloriana, is explained to come from her glorious victory over humanity, as human lips could not pronounce her true name. Her shape is never explicitly described, only that she is enormous and hulking, with slithering limbs. She also possesses telepathic powers, and healing abilities. (In contrast, her consort, Prince Albert, is unexceptionally human.)
The murderer is at the end revealed to be a Restorationist, a member of a secret society dedicated to overthrowing the Queen and the other Old Ones and restoring humanity's freedom. He is implied to be Sherlock Holmes, while his collaborator is explicitly named as John (or James) Watson. Though the Detective solves the case, the murderers escape: nevertheless, Victoria is pleased with the outcome.