Saint Eulogius (c. 819 – 859) was born in Muslim ruled Cordoba, into a wealthy Christian family which had held land in Cordoba from Roman times. He received an excellent education and there is record of him being a priest as of 848. The local Muslim government required Christians to pay a tax in order to practice their faith but otherwise left them in peace. However, in 850, a persecution of Christians was initiated, with several being imprisoned and martyred. Many fled the area, others voluntarily declared themselves Christians and were martyred, and still others hid their faith.
At the start of the persecution, Saint Eulogius was imprisoned for proclaiming his faith boldly. He was then released and ordered to stop his apostolate. He nonetheless persevered in his work and, in 859, was again imprisoned, this time for helping to hide Leocritia, a Muslim convert to Christianity. When questioned, he again refused to renege his faith and so was beheaded on the spot. Saint Leocritia was beheaded four days later.
It is believed that Saint Eulogius was the first to translate part of the Koran. He was described as a great scholar with a keen mind, yet as being very humble. Along with these qualities he had great courage and love of God, refusing to obey the temporal authorities and choosing death rather than to betray Our Lord.