Board Thread:Lore Discussion/@comment-5647122-20140717032717/@comment-24349111-20140717165701

It's not known how many Dragons he commanded, but seeing as he was the right hand of Alduin (atleast I think he was), he probably commanded hundreds of them.

All dragons feared Alduin back then. It's possible that some disagreed with him, but they did not openly show it until the rebellion against them started.