There are many reasons why humans start a war. Most common conflicts involve disputes over territories, money or revenge. Sometimes unusual events can also lead to the start of a war. The so-called War of Jenkins' Ear lasted 9 years, but there is much more to this story than “just” the loss of an ear.
The War of Jenkins' Ear was a conflict between Great Britain and Spain that lasted from 1739 to 1748, with major operations largely ended by 1742. Its unusual name, coined by Thomas Carlyle in 1858, relates to Robert Jenkins, captain of a British merchant ship, who exhibited his severed ear in Parliament following the boarding of his vessel by Spanish coast guards in 1731. This affair and a number of similar incidents sparked a war against the Spanish Empire.
Wikipedia contributors, "Battle of Cartagena de Indias," Wikipedia, The Free Encyclopedia, [http://en.wikipedia.org/w/index.php?title=Battle_of_Cartagena_de_Indias&oldid=572095711] (accessed September 23, 2013) | #goddamnyoulezo