Crown at The Castle, What is It?

Every civilization in the game Age of Empires II The Conquerors have a crown-shaped icon in the castle. The crown Icon will appear after the player reaches the Imperial Age by pressing a hotkey (Ctrl + V). Crowns have their meanings according to the civilization that is being played. If the crown is clicked it means the player want to upgrade unique technology and it requires resources.

Among the existing crown serves to reinforce the troops, strengthening the villager, or add a range. For example, the crown of the Aztecs civilization serves to reinforce the infantry, the crown of the Japanese civilization serves to speed up the pack and unpack trebuchet. The following is the meaning of each crown in the castle in the game AOE II The Conquerors.

1. Crown in Aztecs Civilization (Garland Wars): Add +4 infantry attack.
2. Crown in Britons Civilization (Yeomen): foot archers +1 range, +2 attack tower.
3. Crown in Byzantines Civilization (Logistica) : Catapracts cause trample damage.
4. Crown in Celts Civilization (Furor Celtica) : Siege Workshop Units have +50% hit points.
5. Crown in Chinese Civilization (Rocketry) " : 2 Chu Ko Nu attack, +4 Scorpions.
6. Crown in Franks Civilization (Bearded Axe) : +1 Throwing Axemen range.
7. Crown in Goths Civilization (Anarchy) : Create Huskarl at barracks, Perfusion: Barrack 50% work faster.
8. Crown in Huns Civilization (Atheism) : + 100 years relics, Wonder victories, Apies/ Treason costs -50%
9. Crown in Japanese Civilization (Kataparuto) : Trebuchet fire, pack faster.
10. Crown in Korean Civilization (Shinkichon) : +2 range Mangonels, Onagers, and Siege Onagers
11. Crown in Mayans Civilization (El Dorado) : Eagle Warriors have +40 hit ponts
12. Crown in Mongols Civilization (Drill) : Siege Workshop Units move 50% faster.
13. Crown in Persians Civilization (Mahouts) : War Elephant move 30% faster.
14. Crown in Saracens Civilization (Zealotry) : Camels and Mamelukes +30 hit points.
15. Crown in Spanish Civilization (Supremacy) :  Villagers better in combat
16. Crown in Teutons Civilization (Crenellations) :  +3 range Castles; garrisoned infantry fire arrows.
17. Crown in Turks Civilization (Artillery) : +2 range Bombard Towers, Bambard Cannons, Cannon Galleons.
18. Crown in Vikings Civilization (Berserkergang) : Berserk regererate faster.

Those are the functions of each crown in the game AOEK / AOE2 that can be used to fight in the game, but remember any upgrade for this technology requires resources, so think about more important priorities, technology or economics?