Ypres was a city in northern Belgium that gained a critical importance in the war- an importance that cost almost 1 million men their lives. Virtually every battle the Canadians fought over the next four years was within 100 km of Ypres. It was the northern anchor of the trench lines. The English Channel was only 40 kilometers away and both sides realized that if they won the battle at Ypres they could turn the other sides' flank, sweep in behind the other's trench lines and win the war. This was the dream of the "big breakthrough" - a hope that one great victory would blow a hole in the other sides lines that would lead to victory. The Britsh Army defended the Ypres Sector, and when the Canadians arrived in April, 1915, they were located there as well.