Unit 1 surveys the major regions of the world around 1200 to 1450, just before the great connecting networks of Unit 2. Its purpose is comparison: by the end you should be able to say how any two of these societies were governed, what held them together, and how they made their living.

Three questions apply everywhere, and answering them for each region is the whole unit:

• How is the state organised? Who rules, through what officials, and paid for how?
• What belief system shapes society? Religion supplies law, education, and legitimacy in every region here.
• What is the economic base? Agriculture almost everywhere, but with very different labour systems and levels of trade.

Song China 宋朝中国 is the unit's benchmark state. Its economy became increasingly commercialized 商业化 while remaining largely agrarian 农业为主, supported by rising productive capacity - Champa rice 占城稻, iron and steel production, and transport improvements such as the expanded Grand Canal 大运河.

Government ran through a bureaucracy 官僚体系 staffed by the civil service examination 科举制度, which recruited officials on merit and gave the state unusual administrative depth.

Chinese cultural traditions continued and influenced neighbouring regions - Korea, Japan, and Vietnam adopted writing, bureaucratic models, and belief systems. Neo-Confucianism 新儒学 shaped society, including filial piety 孝道 and the expectation of women's deference. Buddhism 佛教 continued to shape Asian societies and spread further, in forms including Theravada 上座部佛教, Mahayana 大乘佛教, and Tibetan 藏传佛教 Buddhism.

As the Abbasid Caliphate 阿拔斯哈里发国 fragmented, new Islamic political entities emerged, most of them Turkic 突厥人 in origin - among them the Seljuk Empire 塞尔柱帝国, the Mamluk sultanate of Egypt 埃及马穆鲁克苏丹国, and the Delhi Sultanate 德里苏丹国.

Muslim rule continued to expand across Afro-Eurasia through military expansion, merchant activity 商人活动, and the work of missionaries 传教士, especially Sufis 苏非派, whose adaptable practice helped Islam spread.

Muslim states encouraged significant intellectual innovations and transfers 智识创新与传播: advances in mathematics, medicine, and astronomy, and the preservation and extension of Greek learning that later moved into Europe.

Hinduism 印度教, Islam, and Buddhism continued to shape the region, and their meeting produced new devotional forms - the bhakti movement 巴克提运动 in Hinduism and Sufism in Islam, both emphasising direct personal devotion.

State formation showed the unit's theme of continuity and diversity: the Delhi Sultanate ruled much of the north, Vijayanagara 维查耶纳伽尔 arose in the south, and in Southeast Asia the sea-based Majapahit 满者伯夷 and the land-based Khmer Empire 高棉帝国 organised power in different ways.

In the Americas, state systems showed continuity, innovation, and diversity: the Maya 玛雅 city-states, the Mexica 墨西加人 (Aztec) with tribute-based expansion, and the Inca 印加 with a centralised administration, labour obligation, and road system.

In Africa, state systems likewise varied: Great Zimbabwe 大津巴布韦 grew on gold and cattle, Ethiopia 埃塞俄比亚 was a long-established Christian kingdom, and the Hausa Kingdoms 豪萨城邦 sat on trans-Saharan trade routes.

Europe was politically fragmented 政治上分裂, characterised by decentralised monarchies and by feudalism 封建制度 - a system of land held in exchange for service. Monarchs slowly consolidated power, but nothing here approached the administrative reach of Song China.

Christianity 基督教, Judaism 犹太教, and Islam all shaped European society, with the Church supplying law, learning, and legitimacy.

Europe was largely agricultural, dependent on free and coerced labour 自由与强制劳动, including serfdom 农奴制.

The unit's reasoning skill is comparison 比较. The productive comparisons are structural rather than evaluative:

• Centralised administration (Song China, Inca) against fragmented or decentralised rule (Europe, post-Abbasid Islamic states).
• Recruitment by examination against recruitment by birth.
• States funded by tribute (Mexica) against states funded by taxation (Song China).

Worked example (a real AP exam question). AP World short-answer questions regularly ask students to "Identify one similarity" or "Explain one difference" between two regions in a period. A full-mark answer for this unit names the feature and applies it to both: "Both Song China and the Inca Empire used a centralised bureaucracy to govern a large territory, but Song China recruited officials through a competitive examination system while the Inca staffed administration through hereditary elites and a labour obligation." Notice the shape: a comparison must be one feature, two societies. Describing each society in turn and leaving the reader to infer the comparison does not earn the point.

• Learn each region through the same three questions - state, belief system, economy - so any comparison question already has a structure.
• Song China is the benchmark: examination-based bureaucracy, commercialised agriculture, and cultural influence on neighbours.
• For Dar al-Islam, remember the pattern is fragmentation into new states plus continued expansion by trade and Sufi missionaries.
• Give a named state for the Americas and Africa. Mexica tribute, Inca labour obligation, Mali and Great Zimbabwe gold are the reliable examples.
• Europe's distinguishing features are fragmentation, feudalism, and coerced agricultural labour.
• Write comparisons as one feature across two societies, never as two separate descriptions.