The "Inland Empire" of Southern California is the unofficial name of the area adjacent to, and inland from, the Los Angeles and Orange Counties. Previously referred to as the Orange Empire for the area's historical orange groves and industry, the term "Inland Empire" was coined in the 1950's in order to make a distinction between this area and the large, coastal regions, especially Los Angeles. Since the I.E. is not a formal name of the area, there are no proper boundaries, although the San Gabriel Mountains are often used as a starting point. Located about fifty miles from the coast, an "inland" empire was born.

But why "empire?" By definition, the word empire usually indicates a political nature. However, it is a word that also elicits thoughts of size, grandeur, abundance, and productivity. Beginning with its orange industry and growing into the thriving metropolitan area it is today, the IE is often associated with such attributes. Comprised mainly of the San Bernardino and Riverside Counties, the Inland Empire includes over 35 cities, such as Chino, Ontario, Rancho Cucamonga, Loma Linda, Redlands, Riverside, and Corona, among many others. The Inland Empire is not only the second largest region in California, but is also in the top twelve of the entire United States.

Sources and More Information:

http://www.orange-empire.com/
http://en.wikipedia.org/wiki/Inland_Empire_(California)