Was Beowulf originally written with heavy Catholic overtones?

Yes, Beowulf was originally written with heavy Catholic overtones. The poem contains various Christian themes and references, such as the portrayal of Beowulf as a Christ-like figure and the depiction of Grendel as a descendant of Cain from the Bible. The poet also emphasizes the importance of fate and the belief in God's providence throughout the story. These elements suggest that the poem was likely composed by a Christian author who infused their religious beliefs into the narrative.

My question was if Beowulf was orally purely Pagan in nature, but was written with Catholic influence later after the Christians arrived.

Yes, that is a common theory among scholars. Beowulf is believed to have originated as an oral poem with pagan themes and influences, likely composed by a pagan poet. However, as Christianity spread and became the dominant religion in Anglo-Saxon England, it is thought that the poem was eventually written down by Christian scribes who added Christian elements and references to the narrative. This process of layering pagan and Christian themes has led to the complex and multi-faceted nature of Beowulf as we know it today.