According to Catarina Loss, William was a Shadowhunter fit to be a Herondale—brave and twice as self-willed as his grandson who later bore his name. His father was a hard man who taught his sons the Law and made sure they followed them without questions, while his mother was a bit of a hysteric.
In 1828, Will's brother Tobias's name was tainted when it was spread and became widely-known that he allegedly abandoned his comrades in battle.
William is a given name of old Germanic origin. A common Irish form of this name is Liam.
- His grandson, Will Herondale, was named after him.
- The Lost Herondale (first and only mention)