Thor: Son of Asgard is a comic book series published by Marvel Comics from March 2004 to January 2005. Written by Akira Yoshida and illustrated by Greg Tocchini, the series follows Thor's early adventures in Asgard with Sif and Balder. It was originally a limited series of six issues but, thanks to popular demand, it was later extended to an ongoing series that lasted for twelve issues in total.