enberg ▁purchased ▁ 1 5 ▁Cub ist ▁works ▁by ▁Pic asso ▁for ▁ 1 2 , 0 0 0 ▁FF . ▁His ▁collection ▁would ▁soon ▁include ▁ 2 0 ▁works ▁by ▁Pic asso , ▁ 1 0 ▁by ▁Georges ▁Bra que , ▁ 5 ▁by ▁Juan ▁Gr is ▁and ▁ 2 0 ▁by ▁August e ▁Her bin . ▁ ▁Very ▁quickly ▁and ▁despite ▁his ▁lack ▁of ▁experience ▁Ros enberg ▁became ▁the ▁official ▁deal er ▁of ▁the ▁Cub ists ▁purch asing ▁works , ▁in ▁addition ▁to ▁those ▁he ▁already ▁owned , ▁by ▁artist ▁such ▁as ▁Jean ▁Met z inger , ▁Albert ▁G le izes , ▁Fern and ▁Lé ger , ▁Joseph ▁Cs ak y , ▁Henri ▁Laur ens , ▁Georges ▁Val mier ▁and ▁Henri ▁Hay den . ▁Through out ▁World ▁War ▁I ▁Ros enberg ▁served ▁as ▁a ▁moral ▁and ▁financial ▁supp orter ▁of ▁these ▁artists . ▁' With out ▁him ' ▁noted ▁Max ▁Jacob , ▁' a ▁number ▁of ▁pain ters ▁would ▁be ▁drivers ▁or ▁factory ▁workers '. ▁ ▁Pic asso ▁eventually ▁switched ▁over ▁to ▁his ▁brother ▁Paul ▁Ros enberg ' s ▁gallery , ▁who ▁would ▁become ▁his ▁deal er ▁Entre ▁Deux ▁Guer res . ▁ ▁Ros enberg ▁volunte ered ▁for ▁military ▁service ▁in ▁ 1 9 1 5 . ▁He ▁moved ▁into ▁a ▁house ▁at ▁rue ▁Mart he ▁Éd ou ard ▁in ▁Me ud on ▁near ▁the ▁military ▁base , ▁but ▁also ▁retained ▁his ▁Paris ▁a partment ▁at ▁ 2 2 ▁rue ▁Lav ois ier ▁and ▁his ▁H ôtel ▁particulier ▁ 1 9