This is the "Adoring Saints: Right Main Tier Panel" painted in the Italian north, specifically by Jacopo di Cione. Created around 1370, this panel forms part of a larger four-tiered altarpiece that originally stood at the Florentine convent church of San Pier Maggiore.
The painting depicts Christ crowning the Virgin Mary, with a mirrored scene on the other side of the central image. These three panels formed the main level of the altarpiece. The bishop would offer a ring to the convent abbess to signify his spiritual marriage to the church, which may explain the prominence of Saint Catherine of Alexandria.
The saints are arranged in neat rows, looking respectfully towards Christ's coronation. They're painted in detail, with individuality shown through their skin tone, hair colour, and costume. The objects they hold – often instruments used to torture them for their faith – help identify them.
Adoring Saints: Right Main Tier Panel hangs in The National Gallery on Trafalgar Square, London — free to enter. Point your phone at any artwork there and audioguide.london plays a free audio guide in six languages — no app download needed.