Countries with a sovereign monarchy are the United Kingdom, Sweden, Norway, Denmark, the Netherlands, Spain, Luxembourg, Belgium, Brunei, Bahrain, Liechtenstein, Andorra, Jordan, Kuwait, Lesotho, Saudi Arabia, Monaco, Oman, Qatar, Bhutan, Swaziland, Thailand, Cambodia, Japan, Malaysia, Tonga, the United Arab Emirates, Morocco, and Vatican City. Most of the monarchies are hereditary, which means they are passed down from one family member to another, usually father to son.
The United Kingdom and 15 Commonwealth countries are headed by Queen Elizabeth II. These Commonwealth countries once were part of the vast empire that Britain ruled in the 19th and 20th centuries. Elizabeth is queen because her uncle, King Edward VIII, abdicated the throne and was succeeded by his brother, King George VI, Elizabeth's father. She succeeded him because she had no brothers. When Elizabeth dies, tradition dictates that she will be succeeded by her son Charles, who will be succeeded by his son William, who will be succeeded by his son George.
Other monarchies are both elective and hereditary, as is the case of the United Arab Emirates, Cambodia, Kuwait, Lesotho and Swaziland. Other monarchs are installed ex-officio by an administrative body. This is the case with Vatican City and Andorra.