Saint Agnes was martyred in Rome, and buried in the cemetery on the Via Nomentana, where a church was built in her honour in about 350. Her relics are preserved in Rome and may be genuine.
The legends say that she was as young as 12 when she determined to dedicate herself to God and not to marry. When persecution started against Christians, she offered herself for martyrdom and was executed by stabbing.
Her attribute in pictures is a lamb (from agnus; Latin for lamb).