in marginal areas. At one point the Church controlled most of the major vineyards in Germany. Quality instead of quantity become important and spread quickly down the river Rhine. In the 1800s, Napoleon took control of all the vineyards from the Church, including the best, and divided and secularized them. Since then the Napoleonic inheritance laws in Germany broke up the parcels of vineyards further, leading to the establishment of many cooperatives. However, many notable and world-famous wineries in Germany have managed to acquire or hold enough land to produce wine not only for domestic consumption, but also export. An important event took place in 1775 at Schloss Johannisberg in Rheingau, when the courier delivering the harvest permission was delayed for two weeks, with the result that most of the grapes in Johannisberg's Riesling-only vineyard had been affected by noble rot before the harvest began. Unexpectedly, these "rotten grapes" gave a very good sweet wine, which was termed Spätlese, meaning late harvest. From this time, late harvest wines from grapes affected by noble rot have been produced intentionally. The subsequent differentiation of wines based on harvested ripeness, starting with Auslese in 1787, laid the ground for the Prädikat system. These laws, introduced in 1971, define the designations still used today. Geography and climate The German wine regions are some of the most northerly in the world. The main wine-producing climate lies below the 50th parallel, which runs through the regions Rheingau and Mosel. Above this line the climate becomes less conducive to wine production, but there are still some vineyards above this line and the effects of climate change on wine production are growing. Because of the northerly climate, there has been a search for suitable grape varieties (particularly frost resistant and early harvesting ones), and many crosses have been developed, such as Müller-Thurgau in the Geisenheim Grape Breeding Institute. Since several years ago there has been an increase in plantings of Riesling as local and international demand has been demanding high quality wines. The wines are all produced around rivers, mainly the Rhine and its tributaries, often sheltered by mountains. The rivers have significant microclimate effects to moderate the temperature. The soil is slate in the steep valleys, to absorb the sun's heat and retain it overnight. On the rolling hills the soil is lime and clay dominated. The great sites are often extremely steep so they catch the