From the given sentence, extract the phrase (often noun or verb) that carries the given relationship. The generated phrase should be present in the sentence.

Given Relationship: 'be chief of', Sentence: 'At about noon when Illinois Sen. Barack Obama raised his hand to be sworn in as President of the United States and Commander in Chief of all U.S. Armed Forces , the sun blazed down on what had been a blustery , frigid day .'
Chief