Techs:
0. "Early Medieval Warfare" (?)
1. "Tunics and Heraldry", maybe a moral boost or it unlocks an early knight unit
2. "High Medieval Knighthood", maybe Attack/LP/moral boost for knights or it unlocks stables... sth like that.
3. "Horse Armor/Gothic Armor/Heavily armored Cavalry/Late Knighthood", Armor for Cav, unlocks knight-unit or stables...
4. "Vassalage", unlocks military building/units
5. "Individual combat/Knightly combat", moral/defense/offense boost for infantry
6. "Mercenary armies", unlocks some mercenaries or buildings
7. "Longbow/Ranged Combat", unlocks shooting range, range/attack/accuracy boost for ranged units, unlocks sticks etc...
8. "Combined Arms", improves stats for all unit types
9. "Plate Armor/Heavy infantry", armor boost for inf., unlocks building with heavy inf., maybe wedge formation sth like that...
10. "Swiss tactics", some stat boost, unlocks formations like the phalanx, pikes...
11. " Progressive Poliorcetica" (means siege techniques), unlocks siege engineer and some siege engines, more range/accuracy for siege weapons...
12. "Gunpowder", unlocks gunpowder weapons/buildings
13. "Advanced cannons", better siege engineer and cannons
14. "Open-Sea-Trade/Cog", trade boost, unlocks cogs
15. "High Tailgate/Carrack", LP/Attack boost, unlocks carracks
16. "Ship cannons", unlocks cannons on ship/cannonships
17. "Gunport", attack boost for cannonships, unlocks early galeons
18. "Astronomical compass", huge range on campaign map boost
19. "Tailrudder" (correct translated?), speed/maneuverability boost for all ships
20. "Craweel-planking/Hulk", unlocks shipyard, unlocks hulk LP/trade boost (trade boost because ships with craweel-planking could be built wider with more space)
21. "Caulking (and Sinteln)", LP boost, less upkeep (the new innovative combination from caulking with sintel-nails made ships more durable and lead to ship types like cogs)
22. "Caravel", unlocks caravels/new shipyards...
23. "Progressive nautic instruments" (Jacobs rod, nautic charts...), huge range boost on campaign map, speed/maneuverability boost
24. "Expiditions Overseas", unlocks new shipyard, trade/LP boost
25. "Early Modern Warfare", unlocks final military buildings, units, skills and so on...
All of these techs are researched, so they are actual inventions in the tier I placed them.