▁of ▁an ▁early ▁Middle ▁Age ▁share cro pping ▁system ▁known ▁as ▁compl ant , ▁a ▁prec ursor ▁to ▁the ▁mét ay age ▁system . ▁Under ▁this ▁system , ▁the ▁pr ende ur ▁would ▁cultiv ate ▁land ▁owned ▁by ▁a ▁b aille ur . ▁In ▁exchange ▁for ▁using ▁the ▁b aille ur ' s ▁soil , ▁the ▁pr ende ur ▁promised ▁a ▁share ▁of ▁the ▁c rop ▁or ▁its ▁re venue . ▁The ▁length ▁of ▁this ▁partners hip ▁varied ▁and ▁sometimes ▁would ▁extend ▁over ▁gener ations . ▁ ▁References ▁ ▁Category : A gr icult ural ▁labor <0x0A> </s> ▁The ▁Sever ns ide ▁Sir ens ▁are ▁a ▁system ▁of ▁Civil ▁defense ▁sir ens ▁located ▁along ▁the ▁South ▁Se vern ▁Est u ary ▁coast line ▁from ▁Red cl iffe ▁Bay ▁to ▁Pil ning , ▁north west ▁of ▁Br istol . ▁They ▁are ▁activ ated ▁by ▁Av on ▁and ▁Som erset ▁Police ▁in ▁the ▁event ▁of ▁a ▁potential ▁incident ▁at ▁one ▁of ▁the ▁CO MA H ▁sites ▁located ▁in ▁the ▁area , ▁mainly ▁in ▁and ▁near ▁Av on mouth . ▁The ▁system ▁was ▁setup ▁in ▁ 1 9 9 7 ▁following ▁a ▁fire ▁at ▁the ▁Al br ight ▁and ▁Wilson ▁site ▁in ▁ 1 9 9 6 . ▁ ▁Sever ns ide ▁Sir ens ▁Trust ▁ ▁Sever ns ide ▁Sir ens ▁Trust ▁Limited ▁is ▁the ▁organisation ▁responsible ▁for ▁maintain ing ▁the ▁system . ▁It ▁is ▁a ▁registered ▁company ▁( number ▁ 3 3 4 8 0 0 8 ) ▁and ▁char ity ▁( number ▁ 1