Impeachment is the formal process under which public officials are accused and tried for an illegal activity. As a result of—or even during—impeachment, an official can be removed from his/her post. Besides, depending on the outcome of the trial, appropriate punishment is meted out to the accused.
The idea of impeachment comes from Latin, where it means to get caught or entrapped. While in the medieval era, similar French terms implied attacking, in today's world, impeachment means the act of challenging the honesty or credibility of an accused person.
The earliest known instance of impeachment was in the 14th century, when the British Parliament used the process against a noble called Baron Latimer, who was accused of corruption, treason and even the oppression.
The concept of impeachment was adopted in the New World as well. Former British colonies like Virginia, Massachusetts along with a few others included this procedure in their constitutions as soon as the United States of America became independent in 1776.
Back then though, impeachment would at most lead to removal from office, unlike today, when it can lead to criminal charges and conviction. Even in private organizations in countries where impeachment is practiced, there can be a motion to impeach someone for a serious misdemeanor.
One of the most famous impeachment trials was that of US president Bill Clinton in, who went on trial in front of the House of Representatives in December 1998 under charges of perjury and obstruction of justice. This was, of course, regarding the infamous Monica Lewinsky scandal. Clinton, however, was acquitted since only 45 out of 100 senators deemed him guilty of the said charges. In US, a two-third vote (67 votes) is required to find the accused guilty.
In another high-profile American case, in December 2008, then-Illinois governor, Rod Blagojevich (pictured above), was successfully impeached for trying to sell senator Barrack Obama's senate seat, which was left vacant after he was elected to the presidential office. Blagojevich was convicted by a 59-0 vote, removed from his post and was barred from holding any public office in Illinois by another 59-0 vote!