To be honest, Britain did not go very far toward developing principles of war during the 19th century. There were two reasons for this, 1. Britain was heavily committed in fighting small colonial wars such as the Indian Mutiny, and Boer War, not to mention numerous other small conflicts throughout their globe spanning colonial empire; and 2. They did not have a mass army. In 1914 Britain could only field a small six division expeditionary force compared to the mass armies of Germany, France, and Russia.
A short history of the 19th century British Army is probably called for here because it explains much. After the defeat of Napoleon the British army concentrated on its responsibilities in policing England’s colonies and not so much on fighting a major war on the continent. The next major war the British fought against a European opponent was the Crimean War of 1854-1856 and it was not really a major war because it was limited to only one theater and none of the combatants mobilized completely to fight it. The Crimean War was also unsuitable for providing lessons in large scale warfare although it did prove to be a test ground for several new weapons such as shell guns, ironclads, railroads, and rifles.
The next major war Britain fought was the two Boer Wars fought in 1880-1881 and 1899-1902. Again the war was limited to one theater and the main lessons learned were tactical as the Boers were equipped with repeating rifles and some machine guns. The British learned these lessons reasonably well and by 1914 they had changed to a khaki uniform and British riflemen were undoubtedly the best shots of any army in the world. British infantry was trained to fire 15 aimed shots per minute and they were given rewards for marksmanship. The British also had the most combat experience albeit in colonial “small wars” and not mass warfare combat experience against a similarly armed enemy.
The British did not really anticipate involvement in a European land war until 1904 when they began staff talks with the French. They also only committed to a small 6 division expeditionary force. Indeed, British doctrine did not change much at all based on their own experiences and reports on other wars around the globe. The British establishment of 2 machine guns per battalion did not change between 1899 and 1914 despite the demonstration of the machine guns effectiveness in defense during the Russo-Japanese War of 1904-1905.
What principles they did hold to were generally what we would today consider operational or even tactical principles, their navy however had a well-developed strategic doctrine for controlling the world’s oceans. Below are what I consider to be the principles that England adhered to.
- The British emphasized the tactical defensive based on their lessons learned in the Boer War.
- The British utilized concealment in the tactical defensive
- They stressed marksmanship and they were excellent. British marksmanship was so effective that the Germans thought they were facing machine guns in some of the opening battles of the war because British rifle fire was so deadly and accurate.
In conclusion, it is probably fairly safe to say that British doctrine and military principles did not evolve to any great degree between 1815 and the outbreak of World War I because the British saw no need for such planning based on their involvement in colonial warfare and government policy of avoidance in continental struggles if possible. This stance changed in 1904-05 with the advent of the Entente with France but the war came with doctrinal changes still on the drawing table because Britain did not see herself committing anything more than a small expeditionary force to a war they were convinced would be short anyway.
Holley, I. B., Jr. “Ideas and Weapons.” Google Books. 1998. Ideas and Weapons (accessed October 26, 2010).
McEvoy, William P. “Battles – The First Battle of Ypres, 1914.” firstworldwar.com. August 22, 2009. http://www.firstworldwar.com/battles/ypres1.htm (accessed October 26, 2010).
 Holley, I. B., Jr. “Ideas and Weapons.” Google Books. 1998. Ideas and Weapons (accessed October 26, 2010).
 McEvoy, William P. “Battles – The First Battle of Ypres, 1914.” firstworldwar.com. August 22, 2009. http://www.firstworldwar.com/battles/ypres1.htm (accessed October 26, 2010).