They would attack monastaries and plunder gold and tithes in mass.
Side note: Chaucer, the great author, lead a mob to a church and stole in today's equivalent 1 million. Then the next day he took another mob back and got another 500k. Life jt adnt changed much in 500 years.
Viking raid? Actually they did solicit funds to prepare for raids to the south. They had to build a ship and train the crew. It’s why their attacks were so successful.