The eastern stairs of the Apadana at Persepolis show a procession of people bringing tribute to the Achaemenid king, Darius the Great (r.522-486). The relief consists of three parts: the northern wall, with representations of Achaemenid dignitaries; the center, with eight soldiers; and the southern wall, showing representatives of all subject nations (picture above). The relief miraculously survived the sack of Persepolis by the soldiers of Alexander the Great in 330 BCE.
The Bactrians are easily recognizable because they are accompanied by a Bactrian (or double-humped) camel. They are dressed like Median cavalry men, but their trousers are different.
The camel. Notice the little bell. The other presents for the great king are two deep and two shallow bowls.
This Bactrian has a wreath in his hair, which is tied in a knot. He also has earrings, which is unusual. The only people with these jewelry are Bactrians, Arachosians (below) and very important court officials like the mayor of the palace. This may or may not indicate that the Bactrians had a special position in the Achaemenid empire, as the apanage of the crown prince (mathišta).
The top people are probably Gandarans, or, alternatively, Gandarans and Sattagydians - the problem is that the location of Sattagydia ("land of hundred cows") is unclear. However, they certainly lived in the far east, near the Gandarans, who lived in the valley of the river Cophen.
Their tribute is a buffalo, five lances and a shield. These weapons are probably just ornamental, because the real power of the armies of the Punjab was the archery. The people are dressed in short, armless tunics and capes.