1907, Cole, R. W. , The Death Trap 

Robert William Cole (1907) The Death Trap

Germany, France, and Russia go to war with Britain (the French under duress, the others willingly), destroy the British fleet, and invade southern England. Britain is nearly defeated and as profiteering, government bungling and the acts of German agents bring the country close to revolution, a heroic general is called upon to lead the country to victory. With the aid of the Japanese navy (the Japanese remembering Britain as allies from their war with Russia) the General engages the German fleet at the last moment. France switches sides just before the battle, and the enemy fleet is turned away.  [Wikipedia]

Once the British navy is out of the way, we will prove that the theories of eminent British strategists are wrong, by landing eight hundred thousand men, with full equipment of guns and horses, in a few weeks. The road from the coast to London is quite open, and the country as defenceless as a garden. The British have only their regulars and auxiliaries to depend upon, between three and four hundred thousand altogether. They cannot obtain more soldiers, because they have no compulsory military service or universal military training. The stolid British cannot fight on empty stomachs. Even supposing the whole nation flies to arms, which is quite unlikely, of what use would it be ? The British masses are quite untrained, and know nothing of soldiering. Soldiers are not made in a day, or even in a month, and by that time we shall have thrust our sword into the heart of the British Empire. Even supposing they had the men, who is to organise a huge levy ? who drill the men ? and where are the trained officers capable of directing a gigantic army of raw levies ? Then they have not sufficient arms and ammunition. There are not half a million rides in the country, and scarcely sufficient field-guns for the regulars. At the time of the Boer War, their arsenals are nearly depleted of ammunition. We shall find no opposition beyond the three or four hundred thousand men of all arms. My army will surround the British army somewhere on the borders between Surrey and Kent, and annihilate it once and for ever. Then we shall march on to London, and fight our way through the defenceless suburbs. If the British Government does not yield then, we shall bombard London from the suburbs, fight our way through the streets, and capture the House of Parliament , Government Offices, and public buildings. We shall have previously captured Chatham, Sheerness and Woolwich. Then, with the War Office, Admiralty, Foreign Office, Bank Of England, Stock Exchange, Post Office, and Houses of Parliament in our hands, the British Government not have the power of further resistance. The mob of starving people will insist on peace at any price, so that the horrors of invasion may cease, and they can get food. [Extract]

There is a summary/review at: http://www.froginawell.net/japan/2010/05/update-japanese-to-the-rescue/