▁sources ▁class ified ▁those ▁tribes ▁as ▁S iles ian ▁tribes , ▁which ▁were ▁also ▁joint ly ▁class ified ▁as ▁part ▁of ▁Polish ▁tribes . ▁The ▁reason ▁for ▁this ▁classification ▁was ▁the ▁" fund ament ally ▁common ▁culture ▁and ▁language " ▁of ▁S iles ian , ▁Pol an , ▁Mas ov ian , ▁V ist ul an ▁and ▁P omer an ian ▁tribes ▁that ▁" w ere ▁consider ably ▁more ▁closely ▁related ▁to ▁one ▁another ▁than ▁were ▁the ▁German ic ▁tribes ." ▁ ▁According ▁to ▁Pers pect ives ▁on ▁Eth nic ity , ▁written ▁by ▁anth rop ologist ▁V . ▁I . ▁K oz lov ▁and ▁edited ▁by ▁R . ▁H oll oman , ▁the ▁S iles ian ▁tribes , ▁together ▁with ▁other ▁Polish ▁tribes , ▁formed ▁what ▁is ▁now ▁Polish ▁eth nic ity ▁and ▁culture . ▁This ▁process ▁is ▁called ▁eth nic ▁cons olid ation , ▁in ▁which ▁several ▁eth nic ▁communities ▁of ▁the ▁same ▁origin ▁and ▁cogn ate ▁languages ▁merge ▁into ▁one . ▁ ▁Middle ▁A ges ▁The ▁S iles ians ▁lived ▁on ▁the ▁territory ▁that ▁became ▁part ▁of ▁the ▁Great ▁Mor avia ▁in ▁ 8 7 5 . ▁Later , ▁in ▁ 9 9 0 , ▁the ▁first ▁Polish ▁state ▁was ▁created ▁by ▁Duke ▁M iesz ko ▁I , ▁and ▁then ▁expanded ▁by ▁king ▁B oles law ▁I ▁at ▁the ▁beginning ▁of ▁the ▁ 1 1 th ▁century . ▁He ▁established ▁the ▁Bishop ric ▁of ▁W roc ław ▁ ▁in ▁Lower ▁S iles ia ▁in ▁the ▁year ▁ 1 0 0