Trench Warfare 
This course will help people understand trench warfare in World War One (primarily) and its sporadic use since then. It will focus mostly on the history of trench warfare in Europe, its effect on tactics and strategy, and how people fought in trenches.
The Course 
The course is as follows:
- Introduction To Trench Warfare
- Life In The Trenches
- Trench Strategy
- Trench Construction
- Trench Geography
Every fortnight a new assignment will be given. There are three assignments for every topic.
Lesson 1 
Trench warfare is where both opposing armies in a battle have static lines of defense. Trench warfare began when there was a revolution in firepower without similar advances in mobility and communications.
Fortification is nearly as old as warfare itself. However, because of the relatively small sized armies and the because the weapons lacked range, it was traditionally not possible to have a defence that defends more than a short defensive line or an isolated point.
In trench warfare, most of the techniques have existed for years in siege warfare. It was the implementation of these techniques between two armies in the field that was new. Julius Caesar in his Gallic Wars describes how the Roman legions created two huge fortified walls around the city at the Battle of Alesia.
The inner circumvallation, which was 10 miles, held in Vercingetorix's forces, while the contravallation kept relief from reaching them. The Romans, in between the two walls, held the ground. The besieged Gauls, who were facing starvation, eventually surrendered with their relief force unable to fully breach the Roman walls. Mind you, the condition of the Roman army was also tenuous, as they themselves were essentially besieged inside their hastily-constructed walls, and food rationing had pushed their men to the brink of exhaustion, too. In the end, it could be said that the superiority of the Roman cavalry over that of the Gallic forces was the decisive factor.