Abbasids: Ruling dynasty of the Arab world from ad 750 (following the Umayyads) until the Mongol devastation of their capital, Baghdad, 1258. Caliph Harun al-Rashid (786–809) is the best-known Abbasid ruler.

Al-Idrisi: Geographer, “the Strabo of the Arabs.” Born in 1100 and educated in Córdoba; traveled widely, eventually settling in Sicily. For the Norman king Roger II, he wrote The Book of Roger, a systematic geography of the world, still extant.

Arabia Felix: Latin for “happy” or “fortunate” Arabia, term used to refer to the southern Arabian Peninsula.

Ayyubids: Ruling dynasty of Egypt, Syria, northern Mesopotamia and (briefly) Yemen, from the late 12th century until 1250. Established by Salah al-Din (Saladin), who took Jerusalem from Crusader control in 1187 and greatly reduced Crusader principalities.

caliph: Successor of the Prophet Muhammad; leader of the Islamic polity.

Cathay: Name for North China popularized in medieval Europe by Marco Polo. The name derives from the name of the Khitan (or Khitai), a people of Manchuria.

Chandragupta: (ca. 321–ca. 298 BC) Indian emperor, founder of the Maurya dynasty. In 305, defeated Seleucus i, who had invaded India to regain Alexander the Great’s Indian provinces.

Darius: (521–486 BC) King of Persia who consolidated Persian power in the East, including northwestern India.

dinar: Islamic gold coin, first struck in Damascus in 691.

dirham: Islamic silver coin, possibly first struck in the time of the Caliph Uthman (644–656).

ducat: Gold coin introduced by the Republic of Venice in 1284. Used in trade worldwide.

farsakh: (Persian) The distance that can be walked in an hour, or about 5.75 kilometers (3 1/2 mi).

Fatimids: The originally Tunisian dynasty that ruled North Africa from ad 909 to 1171. Founded Cairo in 969.

florin: Europe’s first gold coin, minted in Florence in 1252.

frankincense: Common name for the aromatic resins and oils of trees from the Boswellia family, found chiefly in the southern Arabian Peninsula. Important trade commodity.

Geniza Letters: Vast accumulation of Jewish documents—manuscripts, letters, commercial papers and much else—found in the 1890’s in the synagogue of Fustat (Old Cairo). Many written in Arabic and other languages (but in Hebrew characters), they bear dates between 870 and 1880. Immensely valuable primary material for the study of world trade ranging from northern Europe to India.

Gilgamesh: Legendary Sumerian king, subject of The Epic of Gilgamesh, the most complete version of which was preserved on 11 clay tablets by Assyrian king Ashurbanipal in the seventh century BC.

Hajj: The Muslim pilgrimage to Makkah; one of the five “pillars” of Islam, obligatory once in the lifetime of every Muslim who can afford the journey.

Harappa: Archeological site of an Indus Valley city inhabited since the eighth millennium BC.

Harun al-Rashid: (AD 786–809) Fifth and best-known of the Abbasid caliphs, his rule was marked by relative peace, prosperity and unity in the Islamic empire. A generous patron of artists and scholars. The splendor of his court is remembered in part thanks to its depiction in The 1001 Nights. His diplomatic mission to Charlemagne opened a period of technological, cultural and economic exchange with the West.

Herodotus: (ca. 484–425 BC) Greek historian, dubbed “The Father of History.” Born in Halicarnassus (now Bodrum, Turkey); traveled very widely. The first six parts of his nine-part History introduce most of the peoples of the ancient world and their customs, legends, histories and traditions. The last three treat the Greek–Persian rivalry. He was the first writer to critically evaluate historical, geographical and archeological material.

Ibn Khaldun: (AD 1332–1406) Arab historian and political scientist born in Tunis, one of the first to devise a secular historiography. His classic Al-Muqaddimah (Introduction to History) is a masterpiece of insight and social analysis.

Ilkhanids: (AD 1256–1356) Mongol dynasty that ruled Persia following the conquests of Genghis Khan and his grandson Hülegü Khan. Under Persian influence, the Mongol courts became centers of revitalized culture.

João II: (AD 1455–1495) King under whom Portugal expanded most vigorously in both the Indian Ocean and Brazil.

Ka’bah: A small, cubical stone building, “the House of God,” in the courtyard of the Holy Mosque in Makkah. Muslims believe it was originally built by the Prophet Abraham (Ibrahim) and his son Ishmael (Ismail). All Muslims worldwide turn to the Ka’bah in prayer five times a day.

Mamluks: Dynasty that ruled Egypt and the Levant as an independent state from 1250 until 1517 and as vassals of the Ottomans until 1811. Originally Turkish Kipchak slaves, later also Kurdish and Circassian, they formed a disciplined and well-trained military force that ultimately displaced the Ayyubids.

Sir John Mandeville: Ostensible author of a travel book that appeared in Anglo-Norman French in about 1356, purporting to be an account of the author’s journeys in the East. It is really a compilation, combining geography and natural history with romance and marvels.

mangonel: A military weapon like a catapult for throwing stones and other missiles.

Mansa Musa: African ruler during the zenith of the Mali Empire, 1312 to 1337. During his reign Timbuktu became a center of Muslim culture and scholarship.

Ma’rib Dam: Built around 500 BC, this earthen dam in the Kingdom of Saba (southwestern Arabia) irrigated an area large enough to support a population of 300,000 people. Lasting 1000 years, it was a symbol of Sabaean technological and administrative ability. It collapsed finally in approximately ad 554. Ming: (1368–1644) Chinese dynasty established after the expulsion of the Mongols. The Ming had a century of effective power, but declined in the 16th century and finally succumbed to a rebellion and the Manchu invasion.

Muhammad ibn Tughluq: (1290–1413) Sultan of Delhi, he seized power in 1325 and brought the sultanate to its greatest territorial extent, including the extreme south of India.

myrrh: Aromatic, resinous gum of the thorny flowering tree Commiphora myrrha of the Arabian Peninsula and India, commonly used from early times as incense. Important trade commodity.

Necho II: Pharaoh of Egypt from 610 to 595 BC, he used some 12,000 workers to cut a canal from the Pelusiac branch of the Nile to the Gulf of Suez, the earliest precursor of the modern Suez Canal.

Nestorians: A sect of the Eastern Orthodox (Christian) church named for Nestorius of Syria, who became Bishop of Constantinople in 428 but was exiled to Egypt three years later for heresy. The sect was almost eliminated by the 14th-century Mongol invasions.

Ottomans: A dynasty of rulers established in 1299 in northern Anatolia by Osman i. His successors expanded their territory to include all of Asia Minor and the Levant and much of southeastern Europe and the circum-Mediterranean Middle East. Considered one of the greatest and most powerful civilizations of the modern period. Their zenith under Suleiman I (1520–1566) represents a peak of human creativity, optimism, and artistry.

Parthia: A region corresponding approximately to the modern Iranian province of Khurasan, with part of southern Turkmenistan; seat of the first Persian Empire, which lasted from its defeat of the Seleucids in 238 BC to its defeat by the Sasanids in ad 224.

Pedro Álvares Cabral: (1467–1520) Portuguese navigator who in 1500 sailed the route to India pioneered by Vasco da Gama. To avoid contrary winds, he chose a far westerly course in the Atlantic—far enough west to touch Brazil, which he claimed for Portugal.

Pillars of Hercules: Classical name for promontories flanking the east entrance to the Atlantic from the Mediterranean: Gibraltar in Europe and Mt. Acha in Africa.

Pliny the Younger: (AD 62–ca. 116) Roman politician, orator and writer. His letters are an important source for historians.

portulan or portolan: A navigation manual or book of sailing directions illustrated with charts and descriptions of harbors and coasts.

Ptolemy I Soter: (ca. 367–283 BC) Macedonian general in the army of Alexander the Great who became ruler of Egypt after Alexander’s death (323 BC) and founder of the Ptolemaic dynasty, the first non-Egyptian rulers of Egypt.

Ptolemy II Philadelphus: (ca. 308–246 BC) Son of Ptolemy i, he built Alexandria into the cultural and commercial center of the Greek world, in part by greatly expanding the collection of books in the Library of Alexandria.

qadi: (Arabic) Judge.

Rasulids: (AD 1229–1442) A ruling dynasty of Yemen, of Turkic origin. They broke free of their Ayyubid overlords and located their capital at Ta’iz, which became famous for its artistic and intellectual achievements.

reconquista: (Spanish) The period during which the Christian kingdoms of Spain gradually conquered the territories that had been ruled by the Muslims since 711. The reconquista ended with the fall of Granada in 1492.

Saba and Himyar: Pre-Islamic kingdoms of the southern Arabian Peninsula whose economies were based on trade, especially the export of frankincense and myrrh. Saba was founded in 950 BC; it was conquered in 25 BC by Himyar, whose power collapsed with the collapse of the Ma’rib Dam in the sixth century ad.

Safavids: Iranian dynasty that ruled Persia from 1501 to 1736. The founder of the dynasty crowned himself shah of Azerbaijan in 1501 and subjugated Iran and Iraq in the following 10 years. The Safavids were defeated by the Ottomans in 1514, losing Baghdad as their capital, and built a new capital in Isfahan.

Sasanians: (AD 224–651) Ruling dynasty of the second Persian Empire. Frequently at war with Rome; besieged Constantinople. After 14 years of resistance, was defeated by the new Muslim state as it expanded into Persia. Last king was Yazdagird III.

Seleucids: Greek dynasty descended from Seleucus, one of Alexander the Great’s generals, who initially ruled an area extending from Asia Minor to India.

stele: (Greek; Latin stela) A vertical stone carved with reliefs, inscriptions and ornament.

Strabo: (ca. 63 BC–ad 23) Greek geographer and historian born in what is now Amasya in Turkey. His 47-book Historical Sketches has been almost entirely lost, but his 17-book Geography survived virtually intact, full of rich details of the lands and peoples of the Roman Empire and of such areas as India.

Syriac: Semitic language of the Aramaic group important today because Syriac literature preserves many translations of Greek texts that have not survived in the original.

Timur (Tamerlane): (AD 1336–1405) Descendant of Genghis Khan and founder of the Timurid Empire. By 1369, he had conquered present-day Turkmenistan and established Samarkand as his capital. Later, he extended his conquests between the Caspian and Black Seas, invaded India, captured Baghdad and Damascus, and ruled Anatolia.

topos: (plural: topoi) A recurring concept or idea; a traditional motif or theme in a literary composition.

‘ulama: (Arabic) The transnational community of the learned in Islam, derived from Arabic ‘alim, “one who possesses knowledge.“

wazir: Title of a leading court official in a traditional Islamic regime, often a direct advisor to the ruler.

Yuan: (1246–1368) Mongol dynasty in China that continued the conquests of Genghis Khan and, under Khubilai Khan, returned the capital to Beijing and promoted construction and commerce. Chinese resentment of alien rule culminated in rebellion against the Yuan and the victory of the Ming.