The War between Prussia and Austria (1866) became almost inevitable after the end of hostilities with Denmark. Many Prussians regarded the war as a sad necessity. Moltke, describing his reasons for confidence to War Minister Albrecht von Roon, stated "We have the inestimable advantage of being able to carry our Field Army of 285,000 men over five railway lines and of virtually concentrating them in twenty-five days ... Austria has only one railway line and it will take her forty-five days to assemble 200,000 men." Although there were inevitable mistakes and confusion on the battlefield, Moltke's pre-war calculations were proved correct, and the Austrian army was brought to battle at Königgrätz and destroyed.