The "San Luis Rey" refers to the Mission San Luis Rey de Francia, one of the 21 California missions established by Spanish Franciscan missionaries. Founded in 1798, it is located in Oceanside, California, and is named after Saint Louis, King of France. The mission played a significant role in the spread of Christianity among the Native American population and served as a center for agriculture and education. The mission features a beautiful church, gardens, and historic buildings that reflect the Spanish colonial architecture. Today, it is a popular tourist destination and a site for cultural events, preserving the history of the California missions and the Franciscan order.