Antonina was from Nicaea, a city in Turkey today. At that time the emperor was Maximian who was purging the empire of its Christians.
Antonina was tortured because she would not renounce her faith. She was imprisoned and then taken out so they could force her to sacrifice to idols. Once again, she refused to renounce her faith by performing that unacceptable act, for which she was further tortured.
The story goes that angels descended from Heaven to protect her and pushed back the assailants, thus saving her from further harm. But Antonina’s torturers were persistent and placed her on a hot grill. When she was miraculously unscathed, they sewed her up in a sack and through her in the lake of Nicaea where she ultimately drowned.
Adapted by A.J. Valentini from: Sanidopoulos, J. (2021, April 27). St. Antonina the Martyr of Nicaea. Mystagogy Resource Center. https://www.johnsanidopoulos.com/2016/03/saint-antonina-martyr-of-nicaea.html