Balkh is one of the 34 provinces of Afghanistan. Just like Afghanistan, it is considered that the area of Balkh has a vast history and it has been part of various historical regions.
In 1976 a soviet archeologist Viktor Sarianidi discovered the site of the Bactria-Margiana Archaeological Complex, also known as the Oxus civilization in the area. The word Bactria is the Greek name of the area Balkh which is in northern Afghanistan, while the Margiana is the Greek name of the Persian Satrapy of Margu, which in present day is the capital of Mery in Turkmenistan. As per archeologists BCE was situated where in present day we see Turkmenistan, northern Afghanistan, western Tajikistan and southern Uzbekistan.
The early Greek historian Ctesias believed that the great king of Assyrian Ninus did defeat a Bactrian King Oxylates around 1000 years before the war of Troy (Trojan War). The actual Assyrian record of cuneiform was discovered and decoded in 19th century. Although little credit is given to Greek account by historians.
Some writers also claim that Bactria was the motherland of Indo-European tribes who in 2500-2000 BCE moved to the south-west and to the northern-west into which today is Iran, Pakistan & India. After this the area became the northern province of Achaemenid Empire.
Herzfld also suggested that the Bactria was once a part of the Median Empire. In the 6th century BCE it was conquered by Achaemenid Persians and with the support of Margiana it became the twelfth satrapy of Achaemenids. After that Alexander the Great defeated Darius III of Persia who was later on killed by Bessus the Satrap of Bactria. After killing his predecessor, Bessus tried to organise a national resistance but was captured and delivered to Alexander the Great, and got killed after brutal torture.
Alexander the Great remained successful in conquering Persia & Sogdiana but in the south beyond Oxus he faced great resistance. Macedonians occupied the Bactria after 2 years of war but Alexander was never able to silence the people. After Alexander death his emprise was divided among the several general of his army and Bactria became a part of the Seleucid Empire founded by Seleucus I.
Seleucid King had to face many difficulties in his regime including the attack of Ptolemy II of Egypt. This gave an opportunity to Diodotus Satrap of Bactria to declare independence in 255 BCE. He defeated Sogdiana and was known as the founder of Greco-Bactrian Kingdom. Seleucids attacked the kingdom multiple times but Diodotous and his inheritors were able to maintain themselves against these attacks.
The Greco-Bactria was so powerful at that time that they could expand their territory as far as India. They used the Greek language for administrative purposes. It was then demolished when conquered by Sakas and then by Yuezhi.
Han emperor in 127 BCE sent an investigator Zhang Qian to investigate lands to west of China. His findings were put in writing in the Shiji by Sima Qian in 1st century BCE. They named the land Daxia. He described it as an urban civilisation who live in wall cities. He further mentioned that the country is rich and have sophisticated markets where varieties of objects are being traded; some of these objects are even coming from southern China.
When Zhang Qian visited the area it was not being ruled by a major king and nomadic Yeuzhi was ruling nation so he described people of Daxia as sophisticated but demoralized people who are frightened of war. When Chinese Emperor WuDi came to know about it he showed great interest in developing commercial ties with them after which multiple Chinese embassies were formulated in the area and it set the foundation of Silk Road.