The Incan empire is one of the greatest empires to have no written language. They communicated through Quechua, an oral language, and through visual representation. The other societies listed had some form of written language.

Religious iconography was a product of orthodox Christianity, not Islam. The beliefs of Islam prohibit representing the face of Allah or Mohammed, and as a result religious artwork could contain neither image.

Gothic architecture emerged as the antithesis to the dark, heavy style of Romanesque building that preceded it. Gothic style was defined by more delicate stonework meant to incorporate height, air, and natural light. Buildings became taller and more ornate. Detailing became more delicate in an effort to venerate God, and create structures to venerate man's heavenly blessings. 

Traditional architecture for wealthy families in places as diverse as Afghanistan and Morocco included outdoor space inside a large compound, in part, to give women living in purdah a higher quality of life.

Digging out in case of violent siege was not a reason for having these gardens.

Interior gardens were created to hold prisoners.

It is possible to keep cattle in these gardens, but as they were constructed for wealthy clients who probably already had barns for their cattle, and because getting to the interior garden required walking through the house itself, these gardens were specifically created for people's enjoyment.

The Qur'an does not specify this type of architecture as optimum.

Ibn Battuta lived in the fourteenth century and is remembered for his extensive travels around Africa, Asia, and the Muslim world. He wrote extensively about life in Africa, East Asia, the Middle East, and the Indian subcontinent.

Marco Polo is famous for the voyage he made from Italy to China in the thirteenth century. Much of the popular European understanding of East Asia in the Early Modern period was derived from the writings of Marco Polo.

The survival and preeminence of Greek culture is something we might take for granted. But, its ubiquity and perseverance is owed to several important historical events and empires. The conquests of Alexander the Great established Hellenistic empires all over Eurasia; the Roman assimilation of Greek culture, language, religion, and philosophy ensured the marriage of ancient Greek culture with the elite culture of most of Europe; and the preservation efforts of the Byzantine Empire ensured that the ancient Greek works of philosophy, drama, tragedy, political theory, mathematics, and law were still available to European scholars during the Renaissance.

The Grand Canal was built during the reign of the Sui Dynasty in the early seventh century. The Grand Canal was initially built to facilitate the movement of grain and troops. However, over time, the importance of the canal evolved as it aided population migration and encouraged the growth of trade and industry in eastern China.

The Black Death actually reached Italy first in the 1340s and then spread to the rest of Europe. In Italy, up to 50% of the population in cities were killed. The reason why the Black Death reached Italy first was in part because of its strong trade network with the East, which helped maintain contact with scholars. Furthermore, as the former center of the Roman Empire, Italy had more ancient buildings and other Roman monuments, which later inspired the Renaissance architectural style.

Angkor Wat was built by the Khmer rulers of southeast Asia and was initially a place of Hindu worship, before being converted to a Buddhist temple. It was heavily inspired by Indian architectural designs. Borobudur was a massive temple built by the Srivijayan Empire of Indonesia and was also heavily influenced by Indian architectural style. These are both examples of the spread of Indian culture in southeast Asia during the classical and medieval periods.