List of largest empires in the context of "Achaemenid military"

Alexander III of Macedon (Ancient Greek: Ἀλέξανδρος, romanized: Aléxandros; 20/21 July 356 BC – 10/11 June 323 BC), most commonly known as Alexander the Great, was king of the ancient Greek kingdom of Macedon. He succeeded his father Philip II to the throne in 336 BC at the age of 20, and spent most of his regency conducting a lengthy military campaign throughout parts of Asia and Egypt. By the age of 30, he had created one of the largest empires in history, stretching from Greece to northwestern India. He was undefeated in battle and is widely considered to be one of history's greatest and most successful military commanders.

Alexander was tutored by Aristotle until the age of 16. In 335 BC, shortly after assuming the throne of Macedon, he launched a campaign in the Balkans and reasserted control over Thrace and parts of Illyria before marching on the city of Thebes, which was subsequently destroyed in battle. Alexander then assumed leadership of the League of Corinth, created by his father, and with his authority over all Greeks he launched a pan-Hellenic campaign to invade the Persia.

The Achaemenid Empire (/əˈkiːmənɪd/ ə-KEE-mə-nid; Old Persian: 𐎧𐏁𐏂, Xšāça, lit. 'The Empire' or 'The Kingdom') was an ancient Iranian empire founded by Cyrus the Great of the Achaemenid dynasty in 550 BC. At peak, its territorial extent was roughly 5.5 million square kilometres (2.1 million square miles), making it the largest empire of its time. Based in the Iranian plateau, it stretched from the Balkans and Egypt in the west to the Indus Valley in the east, including Anatolia, Cyprus, Mesopotamia, the Levant, parts of Eastern Arabia, and large parts of Central Asia.

By the 7th century BC, the region of Persis, located in the southwestern part of the Iranian plateau, had been settled by Persians. From Persis, Cyrus rose and defeated Media, Lydia, and the Neo-Babylonian Empire, thus marking the establishment of a new imperial polity in the ancient Near East. While its conquests were largely successful in most regions, the Achaemenid Empire's attempts to expand into Greece proved extremely difficult over the course of decades of wars and multiple kings, ultimately resulting in its defeat in the Greek mainland.

The British Empire comprised the dominions, colonies, protectorates, mandates, and other territories ruled or administered by the United Kingdom and its predecessor states. It began with the overseas possessions and trading posts established by England in the late 16th and early 17th centuries, and colonisation attempts by Scotland during the 17th century. At its height in the 19th and early 20th centuries, it became the largest empire in history and, for a century, was the foremost global power. By 1913, the British Empire held sway over 412 million people, 23 percent of the world population at the time, and by 1920, it covered 35.5 million km (13.7 million sq mi), 24 per cent of the Earth's total land area. As a result, its constitutional, legal, linguistic, and cultural legacy is widespread. At the peak of its power, it was described as "the empire on which the sun never sets", as the sun was always shining on at least one of its territories.

During the Age of Discovery in the 15th and 16th centuries, Portugal and Spain pioneered European exploration of the world, and in the process established large overseas empires. Motivated by the great wealth these empires generated, England, France, and the Netherlands began to establish colonies and trade networks of their own in the Americas and Asia. A series of wars in the 17th and 18th centuries with the Netherlands and France left Britain the dominant colonial power in North America. Britain became a major power in the Indian subcontinent after the East India Company's conquest of Mughal Bengal at the Battle of Plassey in 1757.

Russia, or the Russian Federation, is a country in Eastern Europe and North Asia. It is the largest country in the world, spanning eleven time zones and sharing land borders with fourteen countries. With a population of over 140 million, Russia is the most populous country in Europe and the ninth-most populous country in the world. It is a highly urbanised country, with sixteen of its urban areas having more than 1 million inhabitants. Moscow, the most populous metropolitan area in Europe, is the capital and largest city of Russia; and Saint Petersburg is its second-largest city and cultural centre.

Human settlement on the territory of modern Russia dates back to the Lower Paleolithic. The East Slavs emerged as a recognised group in Europe between the 3rd and 8th centuries AD. The first East Slavic state, Kievan Rus', arose in the 9th century, and in 988, it adopted Orthodox Christianity from the Byzantine Empire. Kievan Rus' ultimately disintegrated; the Grand Duchy of Moscow led the unification of Russian lands, leading to the proclamation of the Tsardom of Russia in 1547. By the early 18th century, Russia had vastly expanded through conquest, annexation, and the efforts of Russian explorers, developing into the Russian Empire, which remains the third-largest empire in history. However, with the Russian Revolution in 1917, Russia's monarchic rule was abolished and eventually replaced by the Russian SFSR—the world's first constitutionally socialist state. Following the Russian Civil War, the Russian SFSR established the Soviet Union with three other Soviet republics, within which it was the largest and principal constituent. The Soviet Union underwent rapid industrialisation in the 1930s, amidst the deaths of millions under Joseph Stalin's rule, and later played a decisive role for the Allies in World War II by leading large-scale efforts on the Eastern Front—rising as a global superpower. With the onset of the Cold War, it competed with the United States for ideological dominance and international influence. The Soviet era of the 20th century saw some of the most significant Russian technological achievements, including the first human-made satellite and the first human expedition into outer space.

The early Muslim conquests or early Islamic conquests (Arabic: الْفُتُوحَاتُ الإسْلَامِيَّة, romanized: al-Futūḥāt al-ʾIslāmiyya), also known as the Arab conquests, were a series of wars initiated in the 7th century by Muhammad, the prophet of Islam. He established the first Islamic state in Medina, Arabia that expanded rapidly under the Rashidun Caliphate and the Umayyad Caliphate, culminating in Muslim rule being established in Asia, Northern Africa, and Southern Europe over the following century. According to historian James Buchan: "In speed and extent, the first Arab conquests were matched only by those of Alexander the Great, and they were more lasting." At their height, the territory that was conquered by the Arab Muslims stretched from Iberia (at the Pyrenees) in the west to India (at Sind) in the east; Muslim control spanned Sicily, most of the Middle East and North Africa, and the Caucasus and Central Asia.

Among other drastic changes, the early Muslim conquests brought about the collapse of the Sasanian Empire and great territorial losses for the Byzantine Empire. Explanations for the Muslim victories have been difficult to discover, primarily because only fragmentary sources have survived from the period. American scholar Fred McGraw Donner suggests that Muhammad's establishment of an Islamic state in Arabia coupled with ideological (i.e., religious) coherence and mobilization constituted the main factor that propelled the early Muslim armies to successfully establish, in the timespan of roughly a century, one of the largest empires in history. Estimates of the total area of the combined territory held by the early Muslim polities at the conquests' peak have been as high as 13,000,000 square kilometres (5,000,000 sq mi). Most historians also agree that, as another primary factor determining the early Muslim conquests' success, the Sasanians and the Byzantines were militarily and economically exhausted from decades of warfare against each other.

The Mongol Empire was the largest contiguous empire in history. Originating in present-day Mongolia in East Asia, the empire at its height stretched from the Sea of Japan to Eastern Europe, extending northward into Siberia and east and southward into the Indian subcontinent, mounting invasions of Southeast Asia, and conquering the Iranian plateau; and reaching westward as far as the Levant and the Carpathian Mountains.

The empire emerged from the unification of several nomadic tribes in the Mongol heartland under the leadership of Temüjin, known by the title of Genghis Khan (c. 1162–1227), whom a council proclaimed as the ruler of all Mongols in 1206. The empire grew rapidly under his rule and that of his descendants, who sent out invading armies in every direction. The vast transcontinental empire connected the East with the West, and the Pacific to the Mediterranean, in an enforced Pax Mongolica, allowing the exchange of trade, technologies, commodities, and ideologies across Eurasia.

Cyrus II of Persia (c. 600 – 530 BC), commonly known as Cyrus the Great, was the founder of the Achaemenid Empire. Hailing from Persis, he brought the Achaemenid dynasty to power by defeating the Median Empire and embracing all of the previous civilized states of the ancient Near East, expanding vastly across most of West Asia and much of Central Asia to create what would soon become the largest empire in history at the time. The Achaemenid Empire's greatest territorial extent was achieved under Darius the Great, whose rule stretched from Southeast Europe in the west to the Indus Valley in the east.

After absorbing the Median Empire, Cyrus conquered Lydia and eventually the Neo-Babylonian Empire, granting him control of Anatolia and the Fertile Crescent, respectively. He also led a major expedition into Central Asia, where his army brought "into subjection every nation without exception" before he allegedly died in battle with the Massagetae, a nomadic Eastern Iranian people, along the Syr Darya in December 530 BC. However, according to Xenophon of Athens, Cyrus did not die fighting and had instead returned to the capital city of Pasargadae. Regardless of the date of his death, he was succeeded by his son Cambyses II, whose campaigns into North Africa led to the conquests of Egypt, Nubia, and Cyrenaica during his short rule.

The History of Iran (also known as Persia) is intertwined with Greater Iran, which is a region encompassing all of the areas that have witnessed significant settlement or influence by the Iranian peoples and the Iranian languages – chiefly the Persians and the Persian language. Central to this region is the Iranian plateau, now largely covered by modern Iran. The most pronounced impact of Iranian history can be seen stretching from Anatolia in the west to the Indus Valley in the east, including the Levant, Mesopotamia, the Caucasus, and parts of Central Asia. It also overlaps or mingles with the histories of many other major civilizations, such as India, China, Greece, Rome, and Egypt.

Iran is home to one of the world's oldest continuous major civilizations, with historical and urban settlements dating back to the 5th millennium BC. The Iranian plateau's western regions integrated into the rest of the ancient Near East with the Elamites (in Ilam and Khuzestan), the Kassites (in Kuhdesht), the Gutians (in Luristan), and later with other peoples like the Urartians (in Oshnavieh and Sardasht) near Lake Urmia and the Mannaeans (in Piranshahr, Saqqez and Bukan) in Kurdistan. German philosopher Georg Wilhelm Friedrich Hegel called the Persians the "first Historical People" in his Lectures on the Philosophy of World History. The sustained Iranian empire is understood to have begun with the rise of the Medes during the Iron Age, when Iran was unified as a nation under the Median kingdom in the 7th century BC. By 550 BC, the Medes were sidelined by the conquests of Cyrus the Great, who brought the Persians to power with the establishment of the Achaemenid Empire. Cyrus' ensuing campaigns enabled the Persian realm's expansion across most of West Asia and much of Central Asia, and his successors would eventually conquer parts of Southeast Europe and North Africa to preside over the largest empire the world had yet seen. In the 4th century BC, the Achaemenid Empire was conquered by the Macedonian Empire of Alexander the Great, whose death led to the establishment of the Seleucid Empire over the bulk of former Achaemenid territory. In the following century, Greek rule of the Iranian plateau came to an end with the rise of the Parthian Empire, which also conquered large parts of the Seleucids' Anatolian, Mesopotamian, and Central Asian holdings. While the Parthians were succeeded by the Sasanian Empire in the 2nd century, Iran remained a leading power for the next millennium, although the majority of this period was marked by the Roman–Persian Wars.