Final answer:
Emma of Normandy's second husband was King Cnut the Great, who she married in 1017 after the death of her first husband, Ethelred the Unready.
Step-by-step explanation:
Emma of Normandy's second husband was King Cnut the Great of Denmark, England, Norway, and parts of Sweden, also known as Canute.
After the death of her first husband, Ethelred the Unready, King of England, Emma married Cnut in 1017 and became Queen Consort of England, Denmark, and Norway.
This marriage strengthened Cnut's claim to the English throne and helped to stabilize the region during a period of Viking conquests and political turmoil.