The wine culture appeared during early settlement, through the incentives from Henry the Navigator. By 1455, the Venetian navigator, Luís de Cadamosto, on visiting Madeira, referred to the excellence of the Madeirense wines, principally the Malvasia castes from the island of Crete, which were being exported in greater numbers. By the end of the 16th century, the celebrated English poet and playwright, William Shakespeare, cited the important export and notoriety of the Madeiran Malvasia castes: in Richard III the Duke of Clarence, the brother of King Edward IV selected a death by drowning in a barrel of Madeira. Later, in Shakespeare's ''Henry IV'' he has Poins censure Falstaff for having sold his soul to the devil for a cup of Madeira wine. The growth of viticulture in Madeira expanded when the sugar industry was attacked by cheaper exports from the New World and Africa, but also from various epidemics and the after-effects of the 1566 privateer sacks. In the 17th century, commercial treaties with England brought increased investments to a business that was still insular. Many commercial wine-makers from England moved to the island, changing the economy, architecture forms and lifestyle of the community. This incremental growth expanded the city with new estates, and a new merchant class that populated the urban quarters. Generally, there were many new three-floor homes with an intermediary service floor, a floor for storage and wine-cellars, and in some cases a tower to watch the port and monitor shipping in the harbour. Various island governors and the convents participated in commercial viticulture. The Companhia de Jesus developed the vast estate of Campanário, which extended from the city to Fajã dos Padres into one of the most successful wines on the island, whereas the nuns of Santa Clara, owners of some large parcels of land, entered into the wine industry, financing the ships that would take their wines to Brazil (and exchanging them for sugar for their sweets business). But, during the 19th century there were epidemics, aggravating the economy and forcing some to return to sugar plantations. In order to maintain the level of development, many landowners tried to plant new more-resistant castes, but of an inferior quality, in order to support the industry.