▁militar istic ▁soci eties ▁largely ▁in ▁response ▁to ▁the ▁T atar ▁ra ids . ▁Its ▁f igh ters ▁were ▁considered ▁form id able ▁and ▁surrounding ▁states ▁such ▁as ▁the ▁kingdom ▁of ▁Poland ▁employed ▁them ▁in ▁times ▁of ▁conflicts . ▁During ▁the ▁ 1 5 0 0 s ▁they ▁were ▁also ▁constantly ▁attack ing ▁the ▁Crime an ▁Tat ars ▁and ▁Ott oman ▁poss essions ▁either ▁to ▁pl under ▁tre asure ▁or ▁liber ate ▁Christian ▁slaves . ▁By ▁six teenth ▁and ▁sevent e enth ▁centuries , ▁the ▁f igh ters ▁began ▁ra iding ▁communities ▁in ▁the ▁Black ▁Sea . ▁These ▁included ▁the ▁cities ▁of ▁V arna , ▁P erek op , ▁Bil hor od , ▁Iz mail , ▁and ▁the ▁Turkish ▁Tre b iz ond , ▁among ▁others . ▁▁▁ ▁In ▁May ▁ 1 6 1 5 , ▁C oss acks ▁on ▁eight y ▁small ▁boats ▁( U kr . ▁Ch ay k ah ), ▁each ▁one ▁carrying ▁about ▁ 5 0 ▁men , ▁went ▁on ▁trip ▁to ▁Turkey . ▁By ▁mid - J une ▁they ▁managed ▁to ▁cross ▁the ▁Black ▁Sea ▁and ▁land ▁on ▁the ▁coast ▁in ▁the ▁vic inity ▁of ▁Ist an bul . ▁After ▁that , ▁the ▁C oss acks ▁captured ▁and ▁set ▁on ▁fire ▁the ▁Ist an bul ▁neighbour ▁of ▁Sc ut ari ▁( now : ▁Ü sk üd ar ), ▁followed ▁by ▁the ▁ports ▁of ▁M ize v na ▁and ▁Arch iu ca . ▁Having ▁s ack ed ▁the ▁city , ▁the ▁C oss acks ▁went ▁back ▁to ▁Ukraine .