<span>King George III needed funds to pay for the artillery used in the French and Indian War. He didn't have them, so he taxed the colonies for something they weren't even a part of. King George taxed the colonists because he felt that he was always there to protect the colonists with his army and all that stuff, so he decided that the colonists should pay him back. The colonists got really mad and some decided that they would not buy the things that King George put taxes on. </span>http://www.answers.com/Q/Why_did_great_Britain_decide_to_tax_the_13_colonies