• Use the Units panel in the Industry Orders screen to make a Merchant.
• Use the Treaties panel in the Diplomacy Orders screen to make a Consulate.
• Once you have the Consulate, make an Embassy with that Tribe.
• Use the Explorer to reveal all the tiles adjacent to the Tribal capital, so you can figure out which one you want to buy.
• It’s important to first buy land in the capital province. If you bought in some other province, then another Great Power could conquer the capital, and you would lose your land.
• Use the online Help for more detailed information about the many wondrous benefits of using the Merchant.