Detailed Instructions: Generate a question which can yield the answer mentioned in the input. Generated question must be answered by the answer provided in input, without using any extra knowledge.
Q: Context : According to the contemporary Chronicle of Fredegar, the Battle of Wogastisburg was a battle between Slavs (Sclav, cognomento Winidi) under King Samo and Franks under King Dagobert I in 631.
Answer : 631
A:
What is the date when Battle of Wogastisburg happened?