The term jerk derives from charqui, a Spanish term for jerked or dried meat, which eventually became jerky in English.  The origins of jerk pork can be traced back to the Cormantee hunters of West Africa, through the Maroons - Jamaican slaves who escaped from the British during the invasion of 1655.  Like in most Caribbean islands, Jamaican recipes and techniques evolved as they were inspired by the cuisines of many different cultures; including British, Dutch, French, Spanish, East Indian, West African, Portuguese, and Chinese.  These inspirations are found to various degrees in modern recipes for jerk. 

Jerk is spiced with three main ingredients:  Scotch bonnet pepper, allspice berry, and thyme.  Other spices and herbs, such as cinnamon, ginger, cloves, garlic, and onion (especially the green part of scallions) may also be used.  Often these spice mixtures are combined with lime or other fruit juice and oil to make a thick paste marinade.  There are as many jerk spice mixtures as there are cooks.  The meat is typically grilled over pimento (allspice) wood.