He served as lieutenant-governor in Java and Sumatra, during which time he wrote a History of Java.
He was very busy, both acting as lieutenant-governor in Java and Sumatra, but also writing a History of Java.
mnli hypothesis: He was very busy, both acting as lieutenant-governor in Java and Sumatra, but also writing a History of Java. premise: He served as lieutenant-governor in Java and Sumatra, during which time he wrote a History of Java.