Nothing, since the term "keep" was not used until the medieval period had ended.
The term "donjon" was used, meaning the strong central tower of a castle - either of timber on an earth mound (in early castles), or of stone in later castles.
Castles in the Middle Ages were used to keep out enemies.
cows.
To bring them luck.
to keep the fire going
The period of time from 500 AD to 1500 AD is called the Middle Ages.
to keep th eking/queen safe
Barns where used for the animals and to keep the food there.
A tower might also have been called a keep.
There was no explorers in the middle ages. When exploration started that is when the middle ages ended.
The third period of the Middle Ages was the Late Middle Ages. The first is called the Early Middle Ages or the Dark Age. The second period was the High Middle Ages.
Early Middle Ages 400 - 700, High Middle Ages 700 - 1300, Late Middle Ages 1300 -1500.
Middle ages