Highest-ranking diplomatic representative of one government to another or to an international organization. As formally defined and recognized at the Congress of Vienna (1815), ambassadors were originally regarded as personal representatives of their country's chief executive rather than of the whole country, and their rank enh1d them to meet personally with the head of state of the host country. Originally, only the principal monarchies exchanged ambassadors; the U.S. did not appoint ambassadors until 1893. Since 1945 all nations have been recognized as equals, and ambassadors or their equivalents are sent to all countries with which diplomatic relations are maintained. Before the development of modern communications, ambassadors were entrusted with extensive powers; they have since been reduced to spokespeople for their foreign offices.

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