In Viking times you held on to land because you were powerful enough to defend it.
You couldn't defend it on your own, so people formed into tightly-knit groups, which we call clans.
The clans were led by a chief (who the Vikings called a landsman). Most of the other men were farmers, but a few were warriors (called bondi), too.
Groups of clans were also grouped into kingdoms, led by a king.
