noun
Refers to the academic field or the historical period itself, typically covering civilizations before the Middle Ages.
大学で古代史を専攻しています。
I'm majoring in ancient history at university.
この博物館には古代史の展示がたくさんある。
This museum has many exhibits on ancient history.
Modern history, referring to more recent historical periods.
Compound of 古代 (kodai, 'ancient times') and 史 (shi, 'history').