This document provides an overview of trench warfare during World War 1. It discusses key battles in 1914-1915 where both sides suffered heavy losses, the new technologies developed during this time, naval warfare, the arrival of American troops, Russia leaving the war, and new allies joining the war. It then focuses on the Gallipoli campaign between Allied and Ottoman forces from April 1915 to January 1916, providing details on the key battles, commanders, objectives, casualties and stalemate that resulted from the trench warfare.