Described in the late 1970s from northern Peru, and only much more recently discovered in southeasternmost Ecuador, the Royal Sunangel is a strikingly plumaged hummingbird. Males are entirely deep blue, with a long, deeply forked tail. Females, in contrast, have dark green upperparts, green-spotted cinnamon underparts with a broad, pale breast-band, and a shallow-forked tail. The species inhabits subtropical elfin forest edge and shrubbery, at elevations between 1,450 m and 2,200 m, and it is partially insectivorous, like many hummingbirds. A new subspecies of the Royal Sunangel, characterized by its reflective indigo-colored forehead, throat, and breast, was recently described from the Cordillera de Azul in northern Peru.