Your Excellency

Excellency is an honorific style given to certain members of an organisation or state. Once entitled to the title "Excellency", the holder usually retains the right to that courtesy throughout his lifetime, although in some cases the title is attached to a particular office, and is held only for the duration of that office.

Generally people addressed as Excellency are heads of state, heads of government, governors, ambassadors, certain ecclesiastics, royalty, and others holding equivalent rank (e.g., heads of international organizations, high commissioners in the Commonwealth of Nations) and the FIFA President.

It is sometimes misinterpreted as a title of office in itself, but in fact is an honorific that precedes various titles (such as Mr. President, and so on), both in speech and in writing. In reference to such an official, it takes the form His or Her Excellency; in direct address, Your Excellency, or, less formally, simply Excellency.

The abbreviation HE is often used instead of His/Her Excellency; alternatively it may stand for His/Her Eminence.

In most republican nations, the head of state is formally addressed as His Excellency.

If a republic has a separate head of government, that official is often addressed as Excellency as well. If the nation is a monarchy, however, the customs may vary. In the case of Australia, all ambassadors, high commissioners, governors and the governor-general and their spouses are entitled to the use of Excellency.

Governors of colonies in the British Empire were entitled to be addressed as Excellency and this remains the position for the governors of what are now known as British Overseas Territories.

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Wikipedia