▁con quest ▁of ▁D acia . ▁ ▁S lave ▁trade ▁There ▁is ▁limited ▁evidence ▁of ▁slaves ▁being ▁used ▁in ▁the ▁economic ▁system ▁of ▁the ▁Da ci ans . ▁The ▁lower ▁classes ▁of ▁D acia ▁( com ati ) ▁were ▁free ▁men ; ▁however , ▁the ▁w ides p read ▁war fare ▁in ▁the ▁region ▁made ▁it ▁one ▁of ▁the ▁most ▁important ▁sources ▁of ▁slaves ▁for ▁the ▁Roman ▁and ▁Greek ▁world , ▁with ▁which ▁they ▁engaged ▁in ▁slave ▁trade . ▁ ▁Her odot us ▁wrote ▁that ▁the ▁Th ra ci ans ▁( which ▁he ▁considered ▁to ▁include ▁the ▁G eta e ) ▁sold ▁their ▁children ▁in ▁sla very ▁to ▁trad ers . ▁Poly b ius ▁wrote ▁that ▁the ▁Gree ks ▁brought ▁slaves ▁" of ▁best ▁quality " ▁from ▁the ▁pe op les ▁living ▁on ▁the ▁sh ores ▁of ▁the ▁Black ▁Sea . ▁ ▁During ▁the ▁late ▁Roman ▁Republic ▁( rough ly ▁between ▁ 1 3 0 ▁BC ▁and ▁ 3 1 ▁BC ), ▁large ▁numbers ▁of ▁Roman ▁den ari i ▁were ▁imported ▁into ▁D acia . ▁There ▁are ▁over ▁ 2 5 , 0 0 0 ▁such ▁co ins ▁in ▁Roman ian ▁collections , ▁most ▁of ▁which ▁were ▁found ▁in ▁large ▁ho ards , ▁a ▁far ▁higher ▁number ▁than ▁anywhere ▁outside ▁the ▁Roman ▁Empire . ▁An ▁explanation ▁for ▁this ▁large ▁amount ▁of ▁imported ▁Roman ▁silver ▁would ▁be ▁that ▁the ▁Da ci ans ▁export ed ▁large ▁numbers ▁of ▁slaves ▁to ▁Rome . ▁Based ▁on ▁the ▁number ▁of ▁co ins , ▁Michael ▁C raw ford ▁estimated