History of the North Sea great herring fishing industry resulting in Scotland becoming a European leader in that industry. During the First Schleswig War (1848–51), the Crimean War (1854–56) and the Second Schleswig War (1864), belligerents took steps to reduce or eliminate commerce in the North Sea by their enemies. In the first Schleswig War, Denmark was able to halt maritime commerce by Germany in the North Sea and in the second, imposed tolls on ships crossing through the Danish straits between the Baltic and North Seas. The Crimean War saw British and French expeditions sent into the Baltic to prevent Russian ships' egress into
History of the forest in Central Europe oak species only three were able to return to Germany and Central Europe from their refuge areas, namely the English oak ("Quercus robur"), sessile oak ("Q. petraea") and downy oak ("Q. pubescens"). By comparison, in North America there are over 80 species of oak. Other types lost considerably in their intraspecific genetic diversity during the return migration such as the white fir ("Abies alba"). Forest flora was pushed back slowly by climatic change. The refuges of the last ice age were probably but not exclusively in southern Europe. A few species on today's Atlantic coast between England and France could