From Latin 'glōria' (fame) — carrying both secular earthly fame and theological divine radiance from Norman French.
High renown or honour won by notable achievements; magnificence or great beauty.
From Anglo-Norman 'glorie,' from Old French 'glorie' (modern French 'gloire'), from Latin 'glōria' (fame, renown, praise), of uncertain deeper etymology. Some scholars propose a connection to PIE *gnō- (to know) via a lost form meaning 'fame, being known,' but this is contested. In Medieval Latin, 'glōria' took on powerful theological meaning — the radiant splendor of God — which the Normans carried into English
The word 'glory' has a split personality: it means both worldly fame (as in 'the glory of Rome') and divine radiance (as in 'the glory of God'). This duality comes from Latin, where 'glōria' covered both human renown and, in Christian usage, the visible splendor of God's presence. The golden halos painted around saints' heads in medieval art were literally called 'glories.'