The Standing Buddha of the Tokyo National Museum is a remarkable example of Greco-Buddhist statuary. Comparable ones can be found in the Musee Guimet in France, and in various museum of the Indian subcontinent. The statue is dated by the museum to the 1st or 2nd century CE.
Many of the stylistic elements in the representations of the statue point to Greek influence:
Some of the standing Buddhas (as the one pictured) were sculpted using the specific Greek technique of making the hands and sometimes the feet in marble to increase the realistic effect, and the rest of the body in another material.
Foucher especially considered Hellenistic free-standing Buddhas as "the most beautiful, and probably the most ancient of the Buddhas", assigning them to the 1st century BCE, and making them the starting point of the anthropomorphic representations of the Buddha ("The Buddhist art of Gandhara", Marshall, p101).
Sometime between the 2nd century BCE and the 1st century CE, the first anthropomorphic representations of the Buddha were developed. These were absent from earlier strata of Buddhist art, which preferred to represent the Buddha with symbols such as the stupa, the Bodhi tree, the empty seat, the wheel, or the footprints. But the innovative anthropomorphic Buddha image immediately reached a very high level of sculptural sophistication, naturally inspired by the sculptural styles of Hellenistic Greece.
There is some debate regarding the exact date for the development of the anthropomorphic representation of the Buddha, and this has a bearing on whether the innovation came directly from the Indo-Greeks, or was a later development by the Indo-Scythians, the Indo-Parthians or the Kushans under Hellenistic artistic influence. Most of the early images of the Buddha (especially those of the standing Buddha) are anepigraphic, which makes it difficult to have a definite dating. The earliest known image of the Buddha with approximate indications on date is the Bimaran casket, which has been found buried with coins of the Indo-Scythian king Azes II (or possibly Azes I), indicating a 30-10 BCE date, although this date is not undisputed. Such datation, as well as the general Hellenistic style and attitude of the Buddha on the Bimaran casket (himation dress, contrapposto attitude, general depiction) would made it a possible Indo-Greek work, used in dedications by Indo-Scythians soon after the end of Indo-Greek rule in the area of Gandhara. Since it already displays quite a sophisticated iconography (Brahma and Śakra as attendants, Bodhisattvas) in an advanced style, it would suggest much earlier representations of the Buddha were already current by that time, going back to the rule of the Indo-Greeks (Alfred A. Foucher and others).
The next Greco-Buddhist findings to be strictly datable are rather late, such as the c.120 CE Kanishka casket and Kanishka's Buddhist coins. These works at least indicate though that the anthropomorphic representation of the Buddha was already extant in the 1st century CE.
From another direction, Chinese historical sources and mural paintings in the Tarim Basin city of Dunhuang accurately describe the travels of the explorer and ambassador Zhang Qian to Central Asia as far as Bactria around 130 BCE, and the same murals describe the Emperor Han Wudi (156-87 BCE) worshiping Buddhist statues, explaining them as "golden men brought in 120 BCE by a great Han general in his campaigns against the nomads." Although there is no other mention of Han Wudi worshiping the Buddha in Chinese historical literature, the murals would suggest that statues of the Buddha were already in existence during the 2nd century BCE, connecting them directly to the time of the Indo-Greeks.
Later, the Chinese historical chronicle Hou Hanshu describes the enquiry about Buddhism made around 67 CE by the emperor Emperor Ming (58-75 CE). He sent an envoy to the Yuezhi in northwestern India, who brought back paintings and statues of the Buddha, confirming their existence before that date:
An Indo-Chinese tradition also explains that Nagasena, also known as Menander's Buddhist teacher, created in 43 BCE in the city of Pataliputra a statue of the Buddha, the Emerald Buddha, which was later brought to Thailand.