In 850, Eulogius was imprisoned during the persecutions raised against the Christian by the Muslim government. While in prison he wrote his "Exhortation to Martyrdom" that was addressed to the virgins Flora and Mary who were beheaded on [[November 24]], 851. Eulogius was freed six days after their death. As Christians faced martyrdom over the following years, Fr. Eulogius encouraged them in their triumphs as he supported the distressed Christian believers.
When the archbishop of Toledo died in 858, Fr. Eulogius was elected his successor. However, his imprisonment for aiding an apostate from
I[[ slam]] prevented his consecration. Leocritia, a member of a noble Moorish family who had converted to Christianity, sought protection of Eulogius from her irate parents. After helping her hide among his friends they were discovered and condemned to death.Eulogius was beheaded on [[March 11]], 859, and Leocritia, who would also be recognized as a saint, followed him on [[March 15]], 859.