Complex sentence: It was first mentioned in a Latin document of Diocese of Wrocław called "Liber fundationis episcopatus Vratislaviensis" from around 1305 as "Frienstad", a new town founded on the ground of the older village Ráj ("Frienstad in Ray").
Split into simpler sentences: It was first mentioned in a Latin document of Diocese of Wrocław called "Liber fundationis episcopatus Vratislaviensis" from around 1305 as "item Frienstad in Ray". It meant that the a new town was being founded on the ground of the older village Ráj ("Ray").