. ▁He ▁sent ▁an ▁anonymous ▁letter ▁to ▁Prince ▁Charles ▁Alexander ▁of ▁Lor raine ▁at ▁the ▁court ▁of ▁Br uss els ▁ple ading ▁for ▁the ▁removal ▁of ▁the ▁Gu ild ' s ▁authority ▁over ▁Ant werp ' s ▁artists ▁and ▁placing ▁that ▁authority ▁in ▁the ▁hands ▁of ▁the ▁Academy , ▁which ▁would ▁determine ▁the ▁fit ness ▁of ▁an ▁artist ▁to ▁pract ise . ▁ ▁As ▁a ▁court ▁painter ▁himself , ▁L ens ▁was ▁in ▁fact ▁not ▁subject ▁to ▁the ▁Gu ild ▁restrictions . ▁ ▁He ▁argued ▁that ▁the ▁mixing ▁of ▁the ▁pain ters ▁with ▁the ▁craft s men ▁in ▁the ▁Gu ild ▁was ▁an ▁unnecessary ▁bur den ▁on ▁the ▁pain ters . ▁ ▁The ▁Prince ▁sent ▁the ▁anonymous ▁letter ▁on ▁to ▁the ▁Ant werp ▁city ▁government , ▁which ▁in ▁turn ▁sought ▁the ▁advice ▁of ▁the ▁Academy . ▁ ▁The ▁Gu ild ▁opposed ▁any ▁reform ▁to ▁the ▁current ▁system . ▁ ▁L ens ▁visited ▁the ▁Prince ▁to ▁ple ad ▁his ▁case ▁in ▁person . ▁ ▁He ▁pre va iled ▁in ▁the ▁end ▁and ▁the ▁em press ▁Maria ▁Ther esa ▁issued ▁on ▁ 2 0 ▁March ▁ 1 7 7 3 ▁an ▁order ▁that ▁liber ated ▁the ▁pain ters , ▁sculpt ors ▁and ▁eng ra vers ▁from ▁the ▁gu ild ▁requirements . ▁ ▁The ▁measure ▁increased ▁the ▁prest ige ▁of ▁L ens ▁who ▁obtained ▁various ▁comm issions ▁to ▁produce ▁alt ar ▁pieces . ▁ ▁L ens ▁remained ▁in ▁function ▁at ▁the ▁Ant werp ▁Academy . ▁ ▁In ▁ 1 7 7 6 ▁he ▁published ▁in ▁Li