The situation
In September 1066 Harold II faced two invasions. He marched north and destroyed a Norwegian army at Stamford Bridge on 25 September. Days later William of Normandy landed on the south coast.
The decision
Harold drove his army back south at speed and chose to fight quickly rather than wait for reinforcements. His men formed a dense shield wall along a ridge.
For hours the wall held against Norman archers, infantry and cavalry. The turning point came when parts of the English line broke ranks to chase retreating Normans down the hill, real or feigned retreats, and were cut down on open ground.
What it cost
By evening Harold was dead, along with his brothers Gyrth and Leofwine. With the English leadership gone, William was crowned at Westminster on Christmas Day 1066. Language, law and land ownership in England were transformed.