King Charles will acknowledge the "darkest days" of colonial rule and slavery while touring Caribbean countries on a visit beginning this month, a Buckingham Palace spokesman said on Friday. The king will first visit the Bahamas and Guyana alone, followed by a trip to Antigua and Barbuda with Queen Camilla, where Charles will give a speech at a meeting of Commonwealth heads of government, the palace said. Charles, 77, who is still receiving treatment for cancer, will visit former colonies that are now independent from Britain and are members of the British Commonwealth.