Unit 3 covers 1648 to 1815, and its organising claim is that different models of political sovereignty affected the relationship among states, and between states and individuals.

The struggle for sovereignty continued to produce varying degrees of political centralisation - but after Westphalia the competition happens between states that recognise each other as sovereign, which is a different game from the one played in Units 1 and 2. Everything in this unit follows from that: the state must now raise revenue, field armies, and manage an economy in permanent competition with rivals who are doing the same.

The English Civil War 英国内战 was a conflict among the monarchy, Parliament, and other elites over their respective roles in the political structure - not a conflict between the crown and the people.

Its outcome, together with the Glorious Revolution 光荣革命, protected the rights of the gentry and aristocracy from absolutism by asserting the rights of Parliament 议会.

Read that carefully, because it is easy to overstate. The settlement protected the rights of a propertied elite against royal power. It did not create popular government, and an answer that treats 1688 as democratic has misread the CED.

Early modern Europe developed a market economy that provided the foundation for its global role. The CED lists the components, and questions reward naming several:

• The Agricultural Revolution 农业革命 raised productivity and increased the supply of food and other agricultural products.
• The importation and transplantation of American crops contributed further to the food supply.
• Labour and trade in commodities were increasingly freed from traditional restrictions 传统限制 imposed by governments and corporate bodies such as guilds.
• The putting-out system, or cottage industry 家庭手工业, expanded as more labourers produced for market in homes and workshops.
• The market economy produced new financial practices and institutions.

The chain worth holding: more food supports more people, freed labour and cottage industry let those people produce for market, and new finance moves the resulting capital. Each link is separately examinable, and together they are the foundation on which Unit 6's industrialisation is built.

The European-dominated worldwide economic network contributed to the agricultural, industrial, and consumer revolutions in Europe.

Mercantilism 重商主义 is the policy frame: the state promotes exports, restricts imports, and acquires colonies to supply raw materials and buy finished goods. Note the direction of causation the CED asserts - the global network is what fed the European transformations, so answers confined to Europe's internal development are incomplete.

The Dutch Republic 荷兰共和国, established by a Protestant revolt against the Habsburg monarchy, developed an oligarchy of urban gentry and rural landholders to promote trade and religious toleration.

The Dutch case matters because it is neither absolutism nor English constitutionalism - a third model, commercially dominant, that shows political form and economic success were not tied together in a single formula.

The competitive state system 竞争性国家体系 led to new patterns of diplomacy and new forms of warfare. After 1648, dynastic and state interests, along with expanding colonial empires, drove European diplomacy.

Two specifics are examinable. Advances in military technology produced new forms of warfare - greater reliance on infantry, firearms, and mobile cannon, and larger standing armies that only a centralising state could pay for. And the inability of the Polish monarchy to consolidate authority over its nobility led to Poland's partition 波兰被瓜分 by Prussia, Russia, and Austria - the clearest demonstration in the course that failure to centralise had a price.

Absolute monarchies limited the nobility's participation in governance but preserved the aristocracy's social position and legal privileges. That trade is the single most useful sentence in the unit: absolutism bought political obedience by leaving social hierarchy untouched.

The CED's named cases:

• Louis XIV 路易十四 and his finance minister Jean-Baptiste Colbert 柯尔贝尔 extended administrative, financial, military, and religious control over the French state.
• Peter the Great 彼得大帝 "westernised" the Russian state and society, transforming political, religious, and cultural institutions; Catherine the Great 叶卡捷琳娜大帝 continued that programme.

The unit's reasoning skill is comparison - the CED's own task is to compare the different forms of political power that developed from 1648 to 1815.

Worked example (a real AP exam question). AP European History short-answer questions here ask, for example, to "Explain one difference between absolutist and constitutionalist forms of government in the period 1648 to 1815." A full-mark answer states the difference in terms that apply to both: "They differed in where sovereignty was located. In absolutist France, Louis XIV concentrated administrative, financial, and military authority in the crown and excluded the nobility from governance. In constitutionalist England, the outcome of the Civil War and the Glorious Revolution located sovereignty in the crown together with Parliament, so that taxation and law required the consent of the propertied elite represented there." Notice the structure: one axis of comparison, then each case measured on it.

• The English Civil War was a conflict among elites about their roles. Do not turn 1688 into democracy.
• Absolutism limited political participation but preserved social privilege. That trade answers many questions.
• Keep a third model ready - the Dutch Republic. It breaks the simple two-way comparison and shows examiners you know the period.
• Poland's partition is the cost of failing to centralise. It is the counter-example the other cases need.
• The economic topics are a chain: agriculture, freed labour, cottage industry, finance. Name several links, not one.
• For comparison questions, choose one axis and measure both cases on it. Two separate descriptions are not a comparison.