Khorasan in the context of "Bukhara"

The ancient history of Afghanistan, also referred to as the pre-Islamic period of Afghanistan, dates back to the prehistoric era and the Helmand civilization around 3300–2350 B.C. Archaeological exploration began in Afghanistan in earnest after World War II and proceeded until the late 1970s during the Soviet–Afghan War. Archaeologists and historians suggest that humans were living in Afghanistan at least 50,000 years ago, and that farming communities of the region were among the earliest in the world. Urbanized culture has existed in the land from between 3000 and 2000 BC. Artifacts typical of the Paleolithic, Mesolithic, Neolithic, Bronze, and Iron ages have been found inside Afghanistan.

After the Indus Valley Civilisation stretched up to northeast Afghanistan, it was inhabited by the Iranic tribes and controlled by the Medes until about 500 BC when Darius the Great (Darius I) marched with his Persian army to make it part of the Achaemenid Empire. In 330 BC, Alexander the Great of Macedonia invaded the land after defeating Darius III of Persia in the Battle of Gaugamela. Much of Afghanistan became part of the Seleucid Empire followed by the Greco-Bactrian Kingdom. Seleucus I Nicator was defeated by Chandragupta Maurya and gave his daughter in a peace treaty. The land was inhabited by various tribes and ruled by many different kingdoms for the next two millennia. Before the arrival of Islam in the 7th century, there were a number of religions practiced in modern-day Afghanistan. Zoroastrianism and Ancient Iranian religions were practiced in western Afganistan (Khorasan and Herat). Hinduism and Buddhism was primarily practiced in regions of Eastern (Kabul) and South-Eastern Afganistan (Kandahar). The Kafiristan (present-day Nuristan) region, in the Hindu Kush mountain range, was not converted until the 19th century. They still follow the ancient Vedic religion (related to modern day Hinduism).

Herat (Pashto, Dari: هرات), or Harat, is one of the thirty-four provinces of Afghanistan, located in the western part of the country. Together with Badghis, Farah, and Ghor provinces, it makes up the north-western region of Afghanistan. Its primary city and administrative capital is Herat city. The province of Herat is divided into about 17 districts and contains over 2,000 villages. It has a population of about 3,780,000, making it the second–most populated province in Afghanistan behind Kabul Province. The population is multi-ethnic but largely Persian-speaking. Herat dates back to Avestan times and was traditionally known for its wine. The city has a number of historic sites, including the Herat Citadel and the Musalla Complex. During the Middle Ages, Herat became one of the important cities of Khorasan and was known as the Pearl of Khorasan.

The province of Herat shares a border with Iran in the west and Turkmenistan in the north, making it an important trading region. The Trans-Afghanistan Pipeline (TAPI) is expected to pass through Herat from Turkmenistan to Pakistan and India in the south. The province has two airports; one is Herat International Airport, in the capital Herat, and the other is at the Shindand Air Base, which is one of the largest military bases in Afghanistan. The Salma Dam, which is fed by the Hari River, is also located in this province.