Fortifications are militaryconstructions designed for defensivewarfare. They have been used for many thousands of years, in a variety of increasingly complex designs. The practice of improving an area's defense is also known as "fortification". Many military installations are known as forts, although they are not always "fortified".
... period began. The intense study of the structure of Sanskrit at this time led to the beginnings of linguistics. The oldest surviving Sanskrit grammar is Paanini's c. ...