Adrian of Nicomedia or Saint Adrian was a Herculian Guard of the Roman Emperor Galerius Maximian. After becoming a convert to Christianity with his wife Natalia (Ναταλία), Adrian was martyred at Nicomedia in Asia-Minor (Turkey). Adrian was the chief military saint of Northern Europe for many ages, second only to Saint George, and is much revered in Flanders, Germany and the north of France.

Nicomedia was an ancient Greek city located in what is now Turkey. In 286, Nicomedia became the eastern and most senior capital city of the Roman Empire, a status which the city maintained during the Tetrarchy system (293–324).