This resourcpack provides players with flags of countries from the medieval period. Currently, I have added 19 flags from the 12th to the 14th century, but in the future, I will add even more flags from different time periods.

Flags:
  +Ayyubid Dynasty (Egypt)
  +Cuzco (Native South American Nation)
  +Delhi Sultante (India Kingdom)
  +England
  +France
  +Goryeo Dynasty (Korea)
  +Holy Roman Empire (Germanic Empire)
  +Japan Kamakura Period (Japan)
  +Khwarezm Empire (Iranian Empire)
  +Kievan-Rus (Russian, Belarus, Ukraine)
  +Kingdom Of Castile (Spain)
  +Majapahit (Indonesia)
  +Mexico City State
  +Mongol Empire (Mongolia)
  +Song Dynasty (China)
  +Teutonic Order
  +Tibetan Empire (Tibetan)
  +Tonga Empire (Native Oceanian Nation)
  +Tran Dynasty (Vietnam)

Give flag commands:
+Ayyubid Dynasty: /give @p paper{CustomModelData:20111,display:{Name:'[{"text":"Ayyubid Dynasty Colour","italic":false}]'}} 1

+Cuzco: /give @p paper{CustomModelData:20112,display:{Name:'[{"text":"Cuzco Colour","italic":false}]'}} 1

+Delhi Sultanate: /give @p paper{CustomModelData:20113,display:{Name:'[{"text":"Delhi Sultanate Colour","italic":false}]'}} 1

+England: /give @p paper{CustomModelData:20114,display:{Name:'[{"text":"England Colour","italic":false}]'}} 1

+France: /give @p paper{CustomModelData:20115,display:{Name:'[{"text":"France Colour","italic":false}]'}} 1

+Goryeo Dynasty: /give @p paper{CustomModelData:20116,display:{Name:'[{"text":"Goryeo Dynasty Colour","italic":false}]'}} 1

+Holy Roman Empire: /give @p paper{CustomModelData:20117,display:{Name:'[{"text":"Holy Roman Empire Colour","italic":false}]'}} 1

+Japan Kamakura Period: /give @p paper{CustomModelData:20118,display:{Name:'[{"text":"Japan Colour","italic":false}]'}} 1

+Khwarezm Empire: /give @p paper{CustomModelData:20119,display:{Name:'[{"text":"Khwarezm Empire Colour","italic":false}]'}} 1

+Kievan-Rus: /give @p paper{CustomModelData:20120,display:{Name:'[{"text":"Kievan-Rus Colour","italic":false}]'}} 1

+Kingdom Of Castile: /give @p paper{CustomModelData:20121,display:{Name:'[{"text":"Kingdom Of Castile Colour","italic":false}]'}} 1

+Majapahit: /give @p paper{CustomModelData:20122,display:{Name:'[{"text":"Majapahit Colour","italic":false}]'}} 1

+Mexico City State: /give @p paper{CustomModelData:20123,display:{Name:'[{"text":"Mexico City State Colour","italic":false}]'}} 1

+Mongol Empire: /give @p paper{CustomModelData:20124,display:{Name:'[{"text":"Mongol Empire Colour","italic":false}]'}} 1

+Song Dynasty: /give @p paper{CustomModelData:20125,display:{Name:'[{"text":"Song Dynasty Colour","italic":false}]'}} 1

+Teutonic Order: /give @p paper{CustomModelData:20126,display:{Name:'[{"text":"Teutonic Colour","italic":false}]'}} 1

+Tibetan Empire: /give @p paper{CustomModelData:20127,display:{Name:'[{"text":"Tibetan Empire Colour","italic":false}]'}} 1

+Tonga Empire: /give @p paper{CustomModelData:20128,display:{Name:'[{"text":"Tonga Empire Colour","italic":false}]'}} 1

+Tran Dynasty: /give @p paper{CustomModelData:20129,display:{Name:'[{"text":"Tran Dynasty Colour","italic":false}]'}} 1