Originally Posted by TheDoc

Brief overview on dual citizenship

In general, countries define citizenship based on one's descent, place of birth, marriage, and/or naturalization. That is, you might be a citizen of a given country for one or more of the following reasons:

• You were born on territory belonging to, or claimed by, that country (often called ius soli, or sometimes jus soli -- Latin for "right of the soil").
• One or both of your parents were citizens of that country (often called ius sanguinis or jus sanguinis -- Latin for "right of the blood").
• You married a citizen of that country (though please note that the practice of granting immediate, automatic citizenship to a foreign spouse is far less prevalent today than it was decades ago).
• You (or one or both of your parents) obtained that country's citizenship by going through a legal process of naturalization.