Adoptionism was a theological, cultural, and political conflict of the late 8th century, receiving its name from a controversy over whether references to Jesus Christ as the adoptive Son of God violated Christian doctrine. Those who believed in Jesus as the adoptive Son of God primarily came from the remnants of the Visigothic Church in modern-day Spain, which is why the controversy is sometimes referred to as Spanish Adoptionism. The Frankish Church under Charlemagne labelled adherents of the belief as heretics, calling them Felicians. The Adoptionist controversy offers an interesting case study for historians and theologians to probe aspects of Christian culture and political power in the early medieval period.