The southern aristocracy declined with the rise of the Indian Ocean trade in the mid 5th century, which led to the court revenues shifting to trade and the disappearance of the caste by the Chen dynasty. As landowning aristocrats were unable to convert cash from the produce of their estates, the resurgence of trade and the money-based economy forced them to break up and sell their lands to the burgeoning merchant class. Influential merchants increasingly occupied political offices, displacing the old aristocrats. On the other hand, the economic developments also drove peasants, unable to cope with inflation or to pay taxes in cash, to become mercenary soldiers, wandering through the country selling their services to the warring princes and plundering the populace. These upheavals devastated the south which eased the fall of the south to the Sui dynasty.