Taxila, also known as Takhkhasilā in Sanskrit, is a significant archaeological site situated about 35 km northwest of Rawalpindi, in Pakistan, and said to be founded by Bharata, younger brother of the Hindu deity Rama and named after Bharata’s son Taksha. It flourished in ancient times due to its important location at the junction of the great trade routes connecting Taxila to the Indian subcontinent and Central Asia. While the origin of the city of Taxila dates back to the 1000 BC, some of its ruins date to the Achaemenid Empire, also known as the First Persian Empire, founded by Cyrus the Great in the 6th century BC, subsequently followed by the Mauryan, Indo-Greek, Indo-Scythian and the Kushan Empire. Taxila has changed hands several times over the centuries, with many empires vying for its control, only due to its strategic location. As the great trade routes connecting Taxila lost importance, the city lost its significance, sank into insignificance, and was finally destroyed by the nomadic Huns in the 5th century.

Although by some accounts, Taxila was considered as one of the earliest, or perhaps the earliest universities in the world, others do not consider it a university in the modern sense, as the teachers living there may not have had official membership of the particular colleges, and there did not seem to have existed the lecture halls and residential quarters. However, the city became a noted centre of learning, including the religious teachings of Buddhism, even several centuries before the birth of Jesus Christ, flourished during the 1st to 5th centuries CE as part of the civilization of Gandhara under various rulers, and continued to attract students from far-off places such as Kashi, Kosala, and Magadha, until the destruction of the city in the 5th century. The students were taught a variety of subjects which included mathematics, sciences, astronomy, medicine, philosophy, politics, literature, even military sciences, and although it was not an institutionalized teaching and learning centre, rather a combination of religious plus secular studies centred around the monasteries.

In 516 BC, Darius the Great, the third Persian King of Kings of the Achaemenid Empire, marched into Afghanistan and conquered Taxila, along with the lands surrounding the Indus River in 515 BC. He controlled the Indus Valley from Gandhar to modern Karachi and Taxila was the capital of Gandhar which was evidently under the Achaemenian rule for more than a century. Finally, King Omphis or Ambhi, the ruler of Taxila, surrendered to the Greek force when Alexander the Great surrounded the city during his invasion of the Indus Valley in 326 BC. During that time, the Greek historians accompanying the Macedonian hero described Taxila as prosperous, wealthy, and well-governed.

However, within a decade after Alexander’s death, Taxila came under the control of the Mauryan Empire, founded by Chandragupta Maurya, who turned it into a provincial capital. It is said that his political and economical advisor, Vishnugupta, popularly known as Chanakya or Kautilya, used to teach at the University of Taxila. Later, during the reign of Emperor Ashoka, the grandson of Chandragupta, the city was made a great seat of Buddhist learning,

After three generations of Mauryan rule, the city was annexed by the Indo-Greek kingdom of Bactria and remained under the Indo-Greeks, until the last Greek king of Taxila was overthrown by the Indo-Scythians, a group of nomadic Iranian people of Saka and Scythian origin, around 90 BC. Their regime continued until around 20 BC, when Gondophares, founder of the Indo-Parthian Kingdom, conquered Taxila and made it his capital.

It is estimated that around 50 AD, the Kushans, a branch of the North-Western Chinese Yue-Chi tribes, conquered the Kabul Valley and Gandhara, and Taxila was taken over from the Parthians by the Kushans under the leadership of Kujula Kadphises. Later, the great Kushan ruler Kanishka founded Sirsukh, the third city on the site, after the second city Sirkap, founded during the Indo-Greek period. During the reign of Emperor Kanishka, the Kushan Empire was stretched from Merve in the west to Khotan in the east with the Aral Sea bounding the north and the Arabian Sea at the south, and Gandhar was an important centre. Huvishka and Vasudeva were two prominent successors of Kanishka.

During the tail end of the Kushan rule, the Gandhara region raided, invaded, plundered, and ruled by several short-lived dynasties of the Sassanids, Kidarites, or little Kushans, and finally the White Huns. Around 470 BC, the White Huns caused extensive devastation and destruction of Taxila's famous Buddhist monasteries and stupas, a fatal blow from which the city would never recover. From 500 to 540 BC, it was under the control of the Hunnic Empire in South Asia and declined gradually and inevitably. Xuanzang, a Chinese Buddhist monk, scholar, and traveler, who visited the site in the 7th century BC, found the city ruined and desolate.

The lost city of Taxila was not identified until later in 1863-64, when Sir Alexander Cunningham, the founder and the first director-general of the Archaeological Survey of India, identified the local site known as Saraikhala with ancient Taxila. Later, Sir John Hubert Marshall worked over twenty years to completely expose the ancient site and its monuments.

The main ruins of Taxila include four major cities belonging to different time periods. The earliest among the ruins belonged to the Hathial section, from where pottery shards dated from as early as the late 2nd millennium BC till the 6th century BC were found. The second earliest are the ruins of Bhir Mound, located adjacent to Hathial, that date from the 6th century BC, followed by the ruins relating to Sirkap, built by the Greco-Bactrian kings during the 2nd century BC. After that, the ruins relating to Sirkap were built by the Greco-Bactrian kings during the 2nd century BC, while the settlements of Sirsuhk were built much later, by the rulers of the Kushan Empire during the 1st to 5th century BC. The structural remains at Taxila include the Bhir mound area, the Giri fortress, the Jandial, and Pippala temples, the palace area at Sirkap, the Jaulian and Mohra Moradu, and stupas like, the Dharmarajika, Kunala, and Bhallar.

The Buddhist stūpas are mound-like or hemispherical structures, decorated with relics, and are used as a place of meditation. As a centre of Buddhist culture, Taxila contained several stupas, and the earliest among them is the Bhir mound, the 1st city in the region, located south of the existing Taxila Museum, rising 65 feet above the Tamra rivulet, the main ancient source of water for the city, and covering a huge area of around 1200 x 730 yards.

The Dharmarajika Stupa is the largest Buddhist establishment in the region that dates from the time of Ashoka, who was also known as Dharmaraja in some Buddhist sources, and the stupa was named after him. The dome of the stupa is 45 feet in height, inside a 150 ft square having a diameter of approximately 115ft on average, excluding the processional path. However, the current site contains the second stupa, constructed over the smaller and humbler original one of the Kushan era, over which the existing dome was constructed. The Dharmarajika Stupa is regarded as a relic depository stupa or Dhatu-Garbha stupa since it is believed that it is one of the locations where the remains of Lord Buddha were buried.

Located on a hill overlooking the ancient city of Sirkap, founded by Greeks in the 2nd century BC, the Kunala Stupa owes its name to Kunala, son of Emperor Ashok and the legitimate heir to the throne. According to the legendary stories, Kunal was blinded by Tishyarakhshita, one of the queens of Ashoka, as she was jealous of his beautiful eyes. According to another version, Tishyarakhshita or Tishyarakhsh was attracted to Kunal, as they were of the same age group, and tried to seduce him. But Kunal thwarted her advance, as she was one of the wives of his father. The lady felt insulted and humiliated at his rejection, and in a fit of anger, she hatched a conspiracy, as a result of which, Kunal was blinded. After that, Kunal left the court, and after years of wandering, Kunala reunited with his father Ashoka after a long time. As the Emperor came to know about the conspiracy, he sentenced Tishyarakhshita to death, but she committed suicide before her execution. Later, Kunal was successfully treated by a doctor from Taxila.

In the local language, the word Jaulian stands for the Seat of Saints. Located on a hill around 300 feet (100 m) in the neighborhood of the city of Sirsukh, Jaulian was built by the Kushans in the 2nd century AD, along with the nearby Mohra Muadu. It was destroyed by the White Huns at the end of the 5th century and had been restored shortly before it was abandoned. The badly damaged Jaulian Stupa is surrounded by 21 beautifully decorated votive stupas, containing several statues. One particular statue Buddha with a hole in the navel is known as the Healing Buddha. The pilgrims would put their fingers in the icon's navel and pray for cures of their ailments. The two-level monastery at Jaulian is similar to that of nearby Mohra Muadu, and some of its rooms also contain preserved statues of the Buddha.

Taxila, in particular for the ruins of the four settlement sites at Bhir, Saraikala, Sirkap, and Sirsukh was designated a UNESCO World Heritage Site in 1980. However, apart from that, there are 18 other archaeological sites in the region, which include among others, the Royal Residence, Sun Temple, Apsidal Temple, Double Headed Eagle Stupa, and the Jain Temple.