Why was the conquest of england. documentented in a tapestry

It was the Bayeaux Tapestry. It depicted the Battle of Hastings were the Norman army led by Duke William also known as William the Conqueror fought the British Saxon army led by King Harold. It depicted the battle from its preparations to the end of the war where Harold was killed and William was the victor. 

The term collage was coined by both  georges braque  and  pablo picasso  in the beginning of the 20th century when collage became a distinctive part of modern art.hope this sorry if there wasn't more of an explanation!