Here is the full list of all 56 Strategy & Tactics: Dark Ages achievements.
Recruit squad Union Pikemen
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Recruit squad Union Musketeers
Apply the Penetrating Arrows Upgrade
Hire the General of the Seventh sons mercenary squad
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Apply the Chain Mails Upgrade
Apply the Training Ground Upgrade
Recruit squad Twin Rivers Archers
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Recruit squad Union Crossbowmen
Recruit squad Town Guards
Recruit squad Landsknechts
Apply the Sharpened Swords Upgrade.
Apply the Stables Upgrade
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Hire the General of the Widowmakers mercenary squad
Recruit squad Militia
Win the Empty Throne scenario.
Recruit squad Baronial Squad
Recruit squad Swordsmen
Recruit squad Peasants.
Hire the General of the Red slashers mercenary squad
Hire the General of the Black company mercenary squad
Complete all main and additional goals in any scenario.
Recruit squad Northern Archers
Recruit squad Free Riders
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Recruit squad Dart Throwers
Recruit squad Sun Phalanx
Recruit squad War Elephants
Recruit squad Twinrivers Templars
Apply the Improved Bows Upgrade
Apply the Sturdy Harness Upgrade
Apply the Practice Range Upgrade
Apply the Sturdy Shields Upgrade
Apply the Breastplates Upgrade
Apply the Lightweight Armor Upgrade
Apply the Stronger Skins Upgrade
Apply the High-Quality Steel Upgrade
Apply the Light Armor Upgrade
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