Given the task definition and input, reply with output. Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.

Olaf Gudrdsson, or as he was named after his death Olaf Geirstad-Alf, was a legendary Norwegian king of the House of Yngling from the Ynglinga saga.
What noble family was Olaf Geirstad-Alf part of?