A "shield wall" is a military formation used primarily in ancient and medieval warfare. Soldiers stand close together, holding their shields side by side to create a protective barrier against enemy attacks. This tactic was effective in defending against projectiles and charges, allowing troops to maintain a strong defensive position. The shield wall was commonly employed by various cultures, including the Vikings and Anglo-Saxons. In this formation, soldiers often interlocked their shields, providing additional strength and stability. The shield wall not only protected the warriors but also allowed them to push back against opponents, making it a crucial strategy in battles during that era.