Asia
Thai and Vietnamese attacks on the Khmer kingdom in Southeast Asia almost annihilated this empire until the French combined Cambodia, Laos, and Vietnam into French Indochina.
Cambodia
Khmer is the official language of Cambodia though the French speaking population is large enough so that French is listed as a second language. During World War II, the Japanese occupied Cambodia, but the French returned in 1946 and granted them independence within the French Union in 1949. In the French--Indochinese War of 1953, Cambodia won full military control. Due to this initial French contact and the constant interactions with Vietnam, Cambodia continues to have a strong French speaking community.
Laos
Much like Cambodia, Laos became a protectorate of France in 1893 and was given semiautonomy in 1949. The Paris agreements of 1954 gave the kingdom of Laos full sovereignty. However, unlike Cambodia who has Vietnam as a major trading partner, Laos has continued their affiliations with France.
Vietnam
The first settlers were Chinese and Cambodians. Then came the Portugese in the 16th century and the French in the early 19th. France conquered the three regions which comprise Vietnam today. They first unified Vietnam in 1887, even then, conflict between the three regions seemed inevitable. The Chinese revolution supplied outside forces to help Vietnam (armed by the U.S.) fight the French. In 1954, they broke the French military campaign and divided the country. By this time, the French had established a strong foundation of French speaking communities in Vietnam.