Given the following context:

Hunter gatherers settled the territory in the stone and iron ages, followed later by Bantu peoples. The population coalesced first into clans and then into kingdoms. The Kingdom of Rwanda dominated from the mid-eighteenth century, with the Tutsi kings conquering others militarily, centralising power and later enacting anti-Hutu policies. Germany colonised Rwanda in 1884 as part of German East Africa, followed by Belgium, which invaded in 1916 during World War I. Both European nations ruled through the kings and perpetuated a pro-Tutsi policy. The Hutu population revolted in 1959. They massacred numerous Tutsi and ultimately established an independent, Hutu-dominated state in 1962. A 1973 military coup saw a change of leadership, but pro-Hutu policy remained. The Tutsi-led Rwandan Patriotic Front launched a civil war in 1990. The presidents of Rwanda and Burundi, both Hutus, died together when their plane was shot down in April 1994. Social tensions erupted in the 1994 genocide, in which Hutu extremists killed an estimated 500,000 to 1 million Tutsi and moderate Hutu. The RPF ended the genocide with a military victory.
Rwanda's economy suffered heavily in wake of the 1994 genocide, but has since strengthened. The economy is based mostly on subsistence agriculture. Coffee and tea are the major cash crops for export. Tourism is a fast-growing sector and is now the country's leading foreign exchange earner. Rwanda is one of only two countries in which mountain gorillas can be visited safely, and visitors pay high prices for gorilla tracking permits. Music and dance are an integral part of Rwandan culture, particularly drums and the highly choreographed intore dance. Traditional arts and crafts are produced throughout the country, including imigongo, a unique cow dung art.

answer the following question:

What country did Belgium invade in 1916? 

Rwanda