It ran from 1001 to 1100.
Eleventh
either is acceptable
a mathematician from the 11th century would be Omar Khayyam.
In the eleventh century
the saxons
At the end of the eleventh century.
In the eleventh century
Leif Ericson.
To finance a campaign
seljuk Turks
To finance a campaign
corvettes were not around in the eleventh century!