Few things in history are as compelling as the duel. Refined and barbaric at the same time, this practice has had a checkered history. The rules of dueling were codified by the Irish in 1777 in the Code Duello (summarized here), which was codified at Clonmel Summer Assizes in 1777.
As evidenced by these documents, dueling was in practice prior to the Irish rules being drafted. The procedure and philosophy behind duels is illustrated in this article.
Dueling gained some traction in America in the 19th century, culminating in the famous Burr-Hamilton affair. There are many more resources to find out more here. For a list of famous duels, you can check out this list. Lest you think men were the only ones dueling, here are a [few short anecdotes]
(http://www.corrieweb.nl/amazon/historicax14.htm) of women dueling. Reportedly, dueling is still legal in Paraguay, as long as both parties are registered blood donors.