Mercury was god of financial gain, commerce, eloquence, messages, communication, travelers, boundaries, luck, trickery and thieves; he also serves as the guide of souls to the underworld.
From the beginning, Mercury had essentially the same aspects as Hermes; wearing winged shoes and a winged hat, and carrying the caduceus. He was often accompanied by a cockerel, herald of the new day, a ram, symbolizing fertility, and a tortoise, referring to Mercury’s legendary invention of the lyre from a tortoise shell.
Like Hermes, he was also a god of messages, eloquence and of trade, particularly of the grain trade. Mercury was also considered a god of abundance and commercial success, particularly in Gaul, where he was said to have been particularly revered. He was also the Romans’ psychopomp, leading newly deceased souls to the afterlife.
Archeological evidence from Pompeii suggests that Mercury was among the most popular of the Roman gods. The god of commerce was depicted on two early bronze coins of the Roman Republic, the Sextans and the Semuncia.