This study aims to identify factors contributing to price fluctuations in artworks after an artist's death. With access to information on seller characteristics from a historical dataset of all art auctions that took place in London between 1741 and 1913, we investigate how trading patterns and network effects affect art sales prices at auctions. Following an artist's death, we capture dynamic effects in sales patterns and find that prices decline by seven percent. We attribute this decline on the confluence of non-strategic and strategic effects, firstly on a frequent lack of access to professional consultation and secondly on changes in trading patterns of art dealers posthumously. Our results highlight the long term influence of those factors on high valued art.