Indus River in the context of "Ecosystem"

Macedonia (/ˌmæsɪˈdoʊniə/ MASS-ih-DOH-nee-ə; Greek: Μακεδονία, Makedonía), also called Macedon (/ˈmæsɪdɒn/ MASS-ih-don), was an ancient kingdom on the periphery of Archaic and Classical Greece, which later became the dominant state of Hellenistic Greece. The kingdom was founded and initially ruled by the royal Argead dynasty, which was followed by the Antipatrid and Antigonid dynasties. Home to the ancient Macedonians, the earliest kingdom was centred on the northeastern part of the Greek peninsula, and bordered by Epirus to the southwest, Illyria to the northwest, Paeonia to the north, Thrace to the east and Thessaly to the south.

Before the 4th century BC, Macedonia was a small kingdom with its capital at Aigai, outside of the area dominated by the great city-states of Athens, Sparta and Thebes, and briefly subordinate to the Achaemenid Empire. During the reign of the Argead king Philip II (359–336 BC), Macedonia (with its capital at Pella) subdued mainland Greece and the Thracian Odrysian kingdom through conquest and diplomacy. With a reformed army containing phalanxes wielding the sarissa pike, Philip II defeated the old powers of Athens and Thebes in the Battle of Chaeronea in 338 BC. Philip II's son Alexander the Great, leading a federation of Greek states, accomplished his father's objective of commanding the whole of Greece when he destroyed Thebes after the city revolted. During Alexander's subsequent campaign of conquest, he overthrew the Achaemenid Empire and conquered territory that stretched as far as the Indus River. For a brief period, his Macedonian Empire was the most powerful in the world – the definitive Hellenistic state, inaugurating the transition to a new period of Ancient Greek civilization. Greek arts and literature flourished in the new conquered lands and advances in philosophy, engineering, and science spread across the empire and beyond. Of particular importance were the contributions of Aristotle, tutor to Alexander, whose writings became a keystone of Western philosophy.

South Asia is the southern subregion of Asia that is defined in both geographical and ethnic-cultural terms. South Asia, with a population of 2.04 billion, contains a quarter (25%) of the world's population. As commonly conceptualised, the modern states of South Asia include Bangladesh, Bhutan, India, the Maldives, Nepal, Pakistan, and Sri Lanka, with Afghanistan also often included, which may otherwise be classified as part of Central Asia. South Asia borders East Asia to the northeast, Central Asia to the northwest, West Asia to the west and Southeast Asia to the east. Apart from Southeast Asia, Maritime South Asia is the only subregion of Asia that lies partly within the Southern Hemisphere. The British Indian Ocean Territory and two out of 26 atolls of the Maldives in South Asia lie entirely within the Southern Hemisphere. Topographically, it is dominated by the Indian subcontinent and is bounded by the Indian Ocean in the south, and the Himalayas, Karakoram, and Pamir Mountains in the north.

Settled life emerged on the Indian subcontinent in the western margins of the Indus River Basin 9,000 years ago, evolving gradually into the Indus Valley Civilisation of the third millennium BCE. By 1200 BCE, an archaic form of Sanskrit, an Indo-European language, had diffused into India from the northwest, with the Dravidian languages being supplanted in the northern and western regions. By 400 BCE, stratification and exclusion by caste had emerged within Hinduism, and Buddhism and Jainism had arisen, proclaiming social orders unlinked to heredity.

The Achaemenid dynasty (Old Persian: 𐏃𐎧𐎠𐎶𐎴𐎡𐏁𐎡𐎹 Haxāmanišyaʰ; Persian: هخامنشی Haxâmaneši; Ancient Greek: Ἀχαιμενίδαι Achaimenidai; Latin: Achaemenides) was a royal house that ruled the Achaemenid Empire, which eventually stretched from Egypt and the Balkans in the west to Central Asia and the Indus Valley in the east.

Around 535 BCE, the Persian king Cyrus the Great initiated a protracted campaign to absorb parts of India into his nascent Achaemenid Empire. In this initial incursion, the Persian army annexed a large region to the west of the Indus River, consolidating the early eastern borders of their new realm. With a brief pause after Cyrus' death around 530 BCE, the campaign continued under Darius the Great, who began to re-conquer former provinces and further expand the Achaemenid Empire's political boundaries. Around 518 BCE, the Persian army pushed further into India to initiate a second period of conquest by annexing regions up to the Jhelum River in what is today known as Punjab. At peak, the Persians managed to take control of most of modern-day Pakistan and incorporate it into their territory.

The first secure epigraphic evidence through the Behistun Inscription gives a date before or around 518 BCE. Persian penetration into the Indian subcontinent occurred in multiple stages, beginning from the northern parts of the Indus River and moving southward. As mentioned in several Achaemenid-era inscriptions, the Indus Valley was formally incorporated into the Persian realm through provincial divisions: Gandāra, Hindush, and Sattagydia.

India, officially the Republic of India, is a country in South Asia. It is the seventh-largest country by area; the most populous country since 2023; and, since its independence in 1947, the world's most populous democracy. Bounded by the Indian Ocean on the south, the Arabian Sea on the southwest, and the Bay of Bengal on the southeast, it shares land borders with Pakistan to the west; China, Nepal, and Bhutan to the north; and Bangladesh and Myanmar to the east. In the Indian Ocean, India is near Sri Lanka and the Maldives; its Andaman and Nicobar Islands share a maritime border with Myanmar, Thailand, and Indonesia.

Modern humans arrived on the Indian subcontinent from Africa no later than 55,000 years ago. Their long occupation, predominantly in isolation as hunter-gatherers, has made the region highly diverse. Settled life emerged on the subcontinent in the western margins of the Indus river basin 9,000 years ago, evolving gradually into the Indus Valley Civilisation of the third millennium BCE. By 1200 BCE, an archaic form of Sanskrit, an Indo-European language, had diffused into India from the northwest. Its hymns recorded the early dawnings of Hinduism in India. India's pre-existing Dravidian languages were supplanted in the northern regions. By 400 BCE, caste had emerged within Hinduism, and Buddhism and Jainism had arisen, proclaiming social orders unlinked to heredity. Early political consolidations gave rise to the loose-knit Maurya and Gupta Empires. Widespread creativity suffused this era, but the status of women declined, and untouchability became an organised belief. In South India, the Middle kingdoms exported Dravidian language scripts and religious cultures to the kingdoms of Southeast Asia.

The Himalayas, or Himalaya, is a mountain range in Asia separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the Earth's highest peaks, including the highest, Mount Everest. More than 100 peaks exceeding elevations of 7,200 m (23,600 ft) above sea level lie in the Himalayas.

The Himalayas abut on or cross territories of six countries: Nepal, India, China, Bhutan, Pakistan and Afghanistan. The sovereignty of the range in the Kashmir region is disputed among India, Pakistan, and China. The Himalayan range is bordered on the northwest by the Karakoram and Hindu Kush ranges, on the north by the Tibetan Plateau, and on the south by the Indo-Gangetic Plain. Some of the world's major rivers, the Indus, the Ganges, and the Tsangpo–Brahmaputra, rise in the vicinity of the Himalayas, and their combined drainage basin is home to some 600 million people; 53 million people live in the Himalayas. The Himalayas have profoundly shaped the cultures of South Asia and Tibet. Many Himalayan peaks are sacred in Hinduism and Buddhism. The summits of several—Kangchenjunga (from the Indian side), Gangkhar Puensum, Machapuchare, Nanda Devi, and Kailash in the Tibetan Transhimalaya—are off-limits to climbers.

Sir Creek (/sər ˈkrik/ sər KREEK), originally Ban Ganga, is a 96 km (60 mi) tidal estuary in the uninhabited marshlands of the Indus River Delta on the border between India and Pakistan. The creek flows into the Arabian Sea and separates Gujarat state in India from Sindh province in Pakistan. The long-standing India-Pakistan Sir Creek border dispute stems from the demarcation "from the mouth of Sir Creek to the top of Sir Creek, and from the top of Sir Creek eastward to a point on the line designated on the Western Terminus". From this point onward, the boundary is unambiguously fixed as defined by the Tribunal Award of 1968.