What are all the proper nouns in this sentence The last group of raiders to terrorize western Europe were the Vikings fierce Scandinavian warriors who almost overran England before King Alfre?

A proper noun is the name or title of a specific person, place, or thing.

The proper nouns in the sentence are:

• Europe (place)
• Vikings (people)
• England (place)
• King (title)
• Alfre (person)

Note: The Word 'Scandinavian' is a proper adjectivedescribing the noun 'warriors'.