Across
1
Advanced stage of human society
4
Long and distinct period of history
6
Metal that replaced bronze in tools
8
Union formed for mutual benefit
9
Government elected by the people
10
Relating to the Middle Ages
11
Armed entry into another territory
14
Ancient empire that conquered much of Europe
Down
2
Legislative assembly of a country
3
Alloy of copper and tin used in early tools
5
Payment made to show submission
6
Freedom from outside control
7
Formal agreement between nations
12
Military blockade of a fortified place
13
Government ruled by a king or queen