Final answer:
Richard's brother John did not rule England while Richard was away on the Third Crusade. John only became the king of England after Richard's death.
Step-by-step explanation:
Richard the Lionheart, who was away during the Third Crusade, left the rule of England under the control of various officials. However, his brother John did not become king until Richard's death in 1199. Therefore, the statement 'Richard's brother John ruled England while he was away' is false. John did attempt to take power during Richard's absence, but was not successful in maintaining control over England until he officially became king after Richard’s death.