Hi all! 
I'm a new poster here, but have been following this great modding community for a couple years now, playing a release here and there, and I have realized after playing Pie's excellent Ancient Europe mod that us Mac players need to have more of these period specific mods!!
So, I have cracked the shell of how modding works ever so barely and am ready to set sail and embark on this long journey of Civ IV modding. But every ship needs a crew, so I am calling out to ALL you pro modders on Civ IV (I hope to see some of my inspirations here like Xyth and Pie_at) to help me make what I consider an excellent idea into a reality.
**KEEP IN MIND THESE ARE ONLY PROPOSALS**
CONCEPT:
The Year is 1066, Europe has arisen out of the Dark Ages to behold a new and precarious power balance. The Feudal System reigns supreme and a nations are held together only by the grip of their rulers. Take the reigns of a feudal Kingdom or empire, and unify as much of Europe as possible before 1500!
proposed Playable Civs:
Kingdom of England
Kingdom of Scotland
Kingdom of Ireland
Kingdom of France
Duchy of Normandy
Kingdom of Spain
Kingdom of Denmark
Kingdom of Sweden
Holy Roman Empire (see Proposed features for more)
Byzantine Empire (see Proposed features for more)
Persian Empire
Tsardom of Russia
Kingdom of Hungary
Kingdom of Poland
Kingdom of Croatia
Arab Sultanate
Maghreb Sultanate
Egyptian Sultanate
proposed Non-playable Vassal civs (Leige in parentheses)
Duchy of Aquitaine (K. France)
Duchy of Brittany (Independent De-jure france)
Duchy of Burgundy (Holy Roman Empire)
Duchy of Swabia (HRE)
Duchy of Lombardy (HRE)
Duchy of Tuscany (HRE)
Duchy of Genoa (HRE)
Duchy of Austria (HRE)
Duchy of Lotharingia (HRE)
Duchy of Thuringia (HRE)
Kingdom of Bohemia (HRE)
Duchy of Brabant (HRE)
Duchy of Silesia (Poland)
Duchy of Transylvania (Hungary)
Duchy of Novogorod (Independent De-jure T. of Russia)
Duchy of Ruthenia (Independent de-jure T. of Russia)
Duchy of Rus (Independent de-jure T of Russia)
Duchy of Crimea (Independent de-jure T of Russia)
Kingdom of Greece (Byzantines)
Kingdom of Serbia (Byzantines)
Kingdom of Bulgaria (Byzantines)
Kingdom of Anatolia (Byzantines)
Kingdom of Armenia (Byzantines)
Duchy of Tarsus (?) (Byzantines)
Duchy of Cyprus (Byzantines)
Duchy of Aegean Islands (Byzantines)
Duchy of Crete (Byzantines)
Emirate of Jerusalem (Arab Sultanate)
Emirate of Syria (Arab Sultanate)
Emirate of Mesopotamia (Arab Sultanate)
Emirate of Lower Nile (Egyptian Sultanate)
Emirate of Abyssinia (Egyptian Sultanate)
Emirate of Alexandria (Egyptian Sultanate)
Emirate of Algeria (Maghreb Sultanate)
Emirate of Morocco (Maghreb Sultanate)
Duchy of Andalusia (Maghreb Sultanate)
Duchy of Portugal (Maghreb Sultanate)
Duchy of Aragon (Maghreb Sultanate)
Duchy of Sicily (Maghreb Sultanate)
Duchy of Naples (Independent)
non-playable Civs
The Papal States
ESSENTIAL FEATURES:
* Vassalage: In the medieval ages, nations had not yet crystallized into united entities, they were held together by the power and prestige of a royal family. Therefore Europe is divided into small regions that owe allegiance to a King. Conquests are made by flipping vassals rather than direct territorial gain.
* De centralization: As travel is slow and authority and resources for control are very limited in this age, Kingdoms are limited in how many cities they can directly control, therefore a King must utilize his vassals to run some provinces to prevent instability and rebellion.
* Rebellion: When a king has overstepped a certain negative relationship Vassals will take up arms, renouncing his protection and going to war for independence. Unhappy cities within a King's territory may declare independence and become new states if he fails to quickly deal with rebellions.
*Stability: The stability of a leader's rule is determined by the traits of the current ruler, plus the traits of the selected civic, plus the average leader-vassal relationship, plus recent war experiences, and more. At below 60% stability vassal states will get a relationship debuff and below 25% relationship new states will form in your most discontent cities. Not keeping constant control over your stability can result very quickly in the breakup of your Kingdom/Empire!
* Diplomacy: War is not the only answer. Gold, soldiers, and territory are great ways to convince vassal states to remain loyal.
* Vassal Armies: vassals are required to provide troops in wartime, and whenever war is declared half of their city garrisons over 2 units become yours for the duration of the war.
* Rulers: In this era, rulers personal traits largely decide the strength of the kingdom. A civilization will receive a buff/debuff for the duration of a ruler's life. Monarchs must train their heirs through special events to be responsible, and republics will generally elect a responsible heir.
*Papal Favor: The pope is the highest moral authority in Europe. The lower your relationship with the pope, the lower your relationship with all good catholic vassals (if another leader has a bad relationship with the pope each negative point will result as a positive point with you)
*Crusades: The pope will call crusades to the holy land on certain years. Most good catholic rulers will vie for control of this region and ALL muslim nations will come to the defense of the current holder of Jerusalem.
* Religious Fervor: Any non-hostile dealings with Muslims will result in displeasure from the Pope, and likewise as a Muslim, dealings with Christians will result in EXTREME displeasure from ALL Muslim states.
* The Patriarch of Constantinople: Eastern Christendom answers to the Patriarch who is represented through the present holder of the City of Constantinople. All features of the patriarch are identical to those of the pope except that the patriarch is not an individual civ.
* Titles: When a King holds certain titles that constitute a historical Empire, he may declare himself Emperor, changing his Civ name to the empire that is created. Also, if all of an emperor's direct territory is captured, and the empire's Vassals are not also subjugated, the Empire will cease to exist until all of its de-jure land is recaptured. If an emperor captures another empire the other empire will simply become property of the captor's empire. Uniting all of the former Roman Empire automatically creates this title and creates new conditions.
PROPOSED CIVICS:
In the medieval age, a leader had limited control of his land's civil development, therefore only certain civic categories are controllable:
Government:
Hereditary Monarchy: Leaders must tailor their heirs to be responsible. +Gold in capital +Production in capital +research in capital -1 relationship with all vassals Unhappiness in all cities without Military presence
Seniority Monarchy: Leaders will be replaced by a family member with random traits. +1/2 Gold in all cities +1/2 Production in all cities +1/2 research in all cities +2 Happiness in all cities
Republic: Leaders will be replaced by a more or less responsible heir. +2 Happiness in capital +1 happiness in All cities +1 relationship with all vassals.
Legal:
Total Crown Authority: -4 Relationship with all vassals. 1 Unhappiness in all cities. With vassal levies, Vassals must give you full control of their militaries in war. Vassals cannot fight each other. +10% Gold in all cities. +25% Military production in all cities. Can draft 5 more units per turn.
Limited Crown Authority: -1 Relationship with all vassals. Enables Vassal Levies. + 5% gold in all cities. +10% Military Production in all cities. Vassal trade controlled by leige.
Confederation: Vassals can trade independently of their leige. Vassals have minimal obligations to leige. +15% Gold in all cities. +15% Military production in all cities.
Labor:
Slavery: Capture or razing of any city, defeat of an *experienced* enemy unit, or plundering an enemy hamlet (or larger) in wartime generates +1 Gold, Production, and Research in all cities for 15 turns. Can complete production in a city for -3 happiness, and -1 population
Serfdom: +50% Gold, Production, and Research in any cities with at least 1 improvement. +5 production for all cities with a hamlet or greater outside. Can complete production in a city for -5 happiness and -2 Population
Caste System: 5 free specialists in every city. Can complete production in a city for gold.
Economy:
Feudal Taxes: 10% of the income every city of every vassal under your control. +20% income and plus 1 unhappiness in all cities. -5 relationship with all vassals. -10 relationship for all vassals with Tithes civic.
Local taxes: 10% of the income of every city of your own. +2 unhappiness in all cities, +1 relationship all vassals.
Tithes: Enables Extort Tithe from cities and vassals (click on this option in diplomacy/city advisor to receive an amount depending on size/population and relationship/happiness of the vassal/city at the cost of -5 relationship/happiness for 15 turns)
Military (if possible to add):
Standing Armies: +100% Military Production in all cities +1 Happiness per military unit in a city.
Vassal Levies: enables Vassal Levies -25% military Production
Mercenary Armies: Allows purchase of 5 military units per turn at 10g each and -1g per turn per unit. -25% Military unit production **At succession, if there is under 100 gold in the treasury, mercenary troops have a 20% chance of rebelling (at wartime they will convert to your one of your enemies' side, in peacetime, they will become barbarians)
This is as far as I will go for now, lets hear some ideas

I'm a new poster here, but have been following this great modding community for a couple years now, playing a release here and there, and I have realized after playing Pie's excellent Ancient Europe mod that us Mac players need to have more of these period specific mods!!
So, I have cracked the shell of how modding works ever so barely and am ready to set sail and embark on this long journey of Civ IV modding. But every ship needs a crew, so I am calling out to ALL you pro modders on Civ IV (I hope to see some of my inspirations here like Xyth and Pie_at) to help me make what I consider an excellent idea into a reality.
**KEEP IN MIND THESE ARE ONLY PROPOSALS**
CONCEPT:
The Year is 1066, Europe has arisen out of the Dark Ages to behold a new and precarious power balance. The Feudal System reigns supreme and a nations are held together only by the grip of their rulers. Take the reigns of a feudal Kingdom or empire, and unify as much of Europe as possible before 1500!
proposed Playable Civs:
Kingdom of England
Kingdom of Scotland
Kingdom of Ireland
Kingdom of France
Duchy of Normandy
Kingdom of Spain
Kingdom of Denmark
Kingdom of Sweden
Holy Roman Empire (see Proposed features for more)
Byzantine Empire (see Proposed features for more)
Persian Empire
Tsardom of Russia
Kingdom of Hungary
Kingdom of Poland
Kingdom of Croatia
Arab Sultanate
Maghreb Sultanate
Egyptian Sultanate
proposed Non-playable Vassal civs (Leige in parentheses)
Duchy of Aquitaine (K. France)
Duchy of Brittany (Independent De-jure france)
Duchy of Burgundy (Holy Roman Empire)
Duchy of Swabia (HRE)
Duchy of Lombardy (HRE)
Duchy of Tuscany (HRE)
Duchy of Genoa (HRE)
Duchy of Austria (HRE)
Duchy of Lotharingia (HRE)
Duchy of Thuringia (HRE)
Kingdom of Bohemia (HRE)
Duchy of Brabant (HRE)
Duchy of Silesia (Poland)
Duchy of Transylvania (Hungary)
Duchy of Novogorod (Independent De-jure T. of Russia)
Duchy of Ruthenia (Independent de-jure T. of Russia)
Duchy of Rus (Independent de-jure T of Russia)
Duchy of Crimea (Independent de-jure T of Russia)
Kingdom of Greece (Byzantines)
Kingdom of Serbia (Byzantines)
Kingdom of Bulgaria (Byzantines)
Kingdom of Anatolia (Byzantines)
Kingdom of Armenia (Byzantines)
Duchy of Tarsus (?) (Byzantines)
Duchy of Cyprus (Byzantines)
Duchy of Aegean Islands (Byzantines)
Duchy of Crete (Byzantines)
Emirate of Jerusalem (Arab Sultanate)
Emirate of Syria (Arab Sultanate)
Emirate of Mesopotamia (Arab Sultanate)
Emirate of Lower Nile (Egyptian Sultanate)
Emirate of Abyssinia (Egyptian Sultanate)
Emirate of Alexandria (Egyptian Sultanate)
Emirate of Algeria (Maghreb Sultanate)
Emirate of Morocco (Maghreb Sultanate)
Duchy of Andalusia (Maghreb Sultanate)
Duchy of Portugal (Maghreb Sultanate)
Duchy of Aragon (Maghreb Sultanate)
Duchy of Sicily (Maghreb Sultanate)
Duchy of Naples (Independent)
non-playable Civs
The Papal States
ESSENTIAL FEATURES:
* Vassalage: In the medieval ages, nations had not yet crystallized into united entities, they were held together by the power and prestige of a royal family. Therefore Europe is divided into small regions that owe allegiance to a King. Conquests are made by flipping vassals rather than direct territorial gain.
* De centralization: As travel is slow and authority and resources for control are very limited in this age, Kingdoms are limited in how many cities they can directly control, therefore a King must utilize his vassals to run some provinces to prevent instability and rebellion.
* Rebellion: When a king has overstepped a certain negative relationship Vassals will take up arms, renouncing his protection and going to war for independence. Unhappy cities within a King's territory may declare independence and become new states if he fails to quickly deal with rebellions.
*Stability: The stability of a leader's rule is determined by the traits of the current ruler, plus the traits of the selected civic, plus the average leader-vassal relationship, plus recent war experiences, and more. At below 60% stability vassal states will get a relationship debuff and below 25% relationship new states will form in your most discontent cities. Not keeping constant control over your stability can result very quickly in the breakup of your Kingdom/Empire!
* Diplomacy: War is not the only answer. Gold, soldiers, and territory are great ways to convince vassal states to remain loyal.
* Vassal Armies: vassals are required to provide troops in wartime, and whenever war is declared half of their city garrisons over 2 units become yours for the duration of the war.
* Rulers: In this era, rulers personal traits largely decide the strength of the kingdom. A civilization will receive a buff/debuff for the duration of a ruler's life. Monarchs must train their heirs through special events to be responsible, and republics will generally elect a responsible heir.
*Papal Favor: The pope is the highest moral authority in Europe. The lower your relationship with the pope, the lower your relationship with all good catholic vassals (if another leader has a bad relationship with the pope each negative point will result as a positive point with you)
*Crusades: The pope will call crusades to the holy land on certain years. Most good catholic rulers will vie for control of this region and ALL muslim nations will come to the defense of the current holder of Jerusalem.
* Religious Fervor: Any non-hostile dealings with Muslims will result in displeasure from the Pope, and likewise as a Muslim, dealings with Christians will result in EXTREME displeasure from ALL Muslim states.
* The Patriarch of Constantinople: Eastern Christendom answers to the Patriarch who is represented through the present holder of the City of Constantinople. All features of the patriarch are identical to those of the pope except that the patriarch is not an individual civ.
* Titles: When a King holds certain titles that constitute a historical Empire, he may declare himself Emperor, changing his Civ name to the empire that is created. Also, if all of an emperor's direct territory is captured, and the empire's Vassals are not also subjugated, the Empire will cease to exist until all of its de-jure land is recaptured. If an emperor captures another empire the other empire will simply become property of the captor's empire. Uniting all of the former Roman Empire automatically creates this title and creates new conditions.
PROPOSED CIVICS:
In the medieval age, a leader had limited control of his land's civil development, therefore only certain civic categories are controllable:
Government:
Hereditary Monarchy: Leaders must tailor their heirs to be responsible. +Gold in capital +Production in capital +research in capital -1 relationship with all vassals Unhappiness in all cities without Military presence
Seniority Monarchy: Leaders will be replaced by a family member with random traits. +1/2 Gold in all cities +1/2 Production in all cities +1/2 research in all cities +2 Happiness in all cities
Republic: Leaders will be replaced by a more or less responsible heir. +2 Happiness in capital +1 happiness in All cities +1 relationship with all vassals.
Legal:
Total Crown Authority: -4 Relationship with all vassals. 1 Unhappiness in all cities. With vassal levies, Vassals must give you full control of their militaries in war. Vassals cannot fight each other. +10% Gold in all cities. +25% Military production in all cities. Can draft 5 more units per turn.
Limited Crown Authority: -1 Relationship with all vassals. Enables Vassal Levies. + 5% gold in all cities. +10% Military Production in all cities. Vassal trade controlled by leige.
Confederation: Vassals can trade independently of their leige. Vassals have minimal obligations to leige. +15% Gold in all cities. +15% Military production in all cities.
Labor:
Slavery: Capture or razing of any city, defeat of an *experienced* enemy unit, or plundering an enemy hamlet (or larger) in wartime generates +1 Gold, Production, and Research in all cities for 15 turns. Can complete production in a city for -3 happiness, and -1 population
Serfdom: +50% Gold, Production, and Research in any cities with at least 1 improvement. +5 production for all cities with a hamlet or greater outside. Can complete production in a city for -5 happiness and -2 Population
Caste System: 5 free specialists in every city. Can complete production in a city for gold.
Economy:
Feudal Taxes: 10% of the income every city of every vassal under your control. +20% income and plus 1 unhappiness in all cities. -5 relationship with all vassals. -10 relationship for all vassals with Tithes civic.
Local taxes: 10% of the income of every city of your own. +2 unhappiness in all cities, +1 relationship all vassals.
Tithes: Enables Extort Tithe from cities and vassals (click on this option in diplomacy/city advisor to receive an amount depending on size/population and relationship/happiness of the vassal/city at the cost of -5 relationship/happiness for 15 turns)
Military (if possible to add):
Standing Armies: +100% Military Production in all cities +1 Happiness per military unit in a city.
Vassal Levies: enables Vassal Levies -25% military Production
Mercenary Armies: Allows purchase of 5 military units per turn at 10g each and -1g per turn per unit. -25% Military unit production **At succession, if there is under 100 gold in the treasury, mercenary troops have a 20% chance of rebelling (at wartime they will convert to your one of your enemies' side, in peacetime, they will become barbarians)
This is as far as I will go for now, lets hear some ideas
