Eventually, by the turn of the twentieth century, all three of these streams were united into one family of congregations under the leadership and care of the Dutch Mennonite Mission with missionaries from Netherlands, Russia, and later Germany and Switzerland. Soon after the outbreak of World War II the German forces invaded and occupied Netherlands. The response of the government of the Netherlands East Indies was to arrest German nationals there, including the two German Mennonite missionaries with the Dutch Mennonite Mission in Java.
Over time, these three congregations merged into one under Dutch Mennonite Mission leadership, with missionaries from Netherlands, Russia, and later Germany and Switzerland. During World War II, German forces invaded the Netherlands East Indies, leading to the arrest of German nationals there, including two German Mennonite missionaries working with the Dutch Mennonite Mission in Java.