Hang with me. I see you snoozing as I prepare to mention wool. No knitting involved here. This is fiber arts as related to battle training, children, and household productivity!
Every Viking home and village needed ropes and cords - lots of it. They used it on their clothing, boats, you name it. And those Vikings also had children hanging about that had lots of energy. So they figured out a way to occupy the kids and put that energy to good use - making whipcord! To ensure they'd stick with the job, it developed into a fun game.
Here you see four "bobbins" with attached wool yarn hanging from a plant hook. Vikings would've used a tree branch, but we made due. The bobbins would normally be carved wood or even plain stones. Something with some heft. Water-filled bottles work great. Enter in two enthusiastic, fair-haired Viking boys.
"Leif" and "Rolf" each hold a bobbin in each hand. Two bobbins are wound with black yarn, two with white. They toss/trade bobbins, right hand to right hand, left hand to left hand. As the bobbins are traded back and forth, the yarn is braided into a very sturdy cord. As they boys got the hang of it, they aimed to set new speed records. This productive game helped train young Vikings for battle, increasing eye-hand coordination. Even our 4 yr old figured this out! Not complicated, but highly entertaining!
If you want to try to make your own Viking whipcord, you can find instructions and read all about it on this pdf.