Forge of Empires Military Units

We can divide Forge of Empires units by the age they show up. There are currently six ages with a few types of units each.

1. Bronze Age Units 
2. Iron Age Units
3. Early Middle Age Units
4. High Middle Age Units
5. Late Middle Age Units
6. Colonial Age Units

Units taking part of battles play an important role in the game. Aside from ages, they could also be sort by type: Light Infantry, Heavy Infantry, Cavalry, Range Units and Artillery. To achieve such an unit, you need to build the specific barrack. Each of these barracks have four slots available for supplies and gold. The fifth sloth needs diamonds to unlock.
Every single age unloads one unit per type. Considering we are in Bronze Age. We will unlock one Light Infantry unit, one Heave Infantry unit, one Cavalry unit, one Range unit and one Artillery unit. This process repeats throughout the next 5 ages. Each age - 5 units to research.