the economy of the commonwealth was dominated by feudal agriculture based on the plantation system (serfs). slavery was forbidden in poland in the 15th century, and formally abolished in lithuania in 1588, replaced by the second enserfment. typically a nobleman's landholding comprised a "folwark", a large farm worked by serfs to produce surpluses for internal and external trade. this economic arrangement worked well for the ruling classes in the early era of the commonwealth, which was one of the most prosperous eras of the grain trade. the economic strength of commonwealth grain trade waned from the late 17th century on. trade relationships were disrupted by the wars, and the commonwealth proved unable to improve its transport infrastructure or its agricultural practices. serfs in the region were increasingly tempted to flee. the commonwealth's major attempts at countering this problem and improving productivity consisted of increasing serfs' workload and further restricting their freedoms in a process known as export-led serfdom.