Aelswith

Aelswith is Alfred's queen, devout and unbending, watching over Wessex with a suspicion of anything pagan or unruly. She distrusts Uhtred on sight, sees his Danish upbringing as a threat to her husband's fragile kingdom, and speaks her mind with a sharpness few at court dare match.

Eliza Butterworth plays her as flint rather than decoration, a woman whose piety is armor as much as belief. The show could easily sideline her as the pious wife, but she's given real friction with Uhtred and real stake in Wessex's survival, and Butterworth makes her certainty feel earned rather than shrill.