The last dragon worth any note bathed Sigurd's blade Gram with its blood, so no, they weren't ridden as far back as I can remember. Not to any great benefit, anyway.

[ a black nail itches his cheek, something of a softer smile barely whisking the corners of his lips as he regards hiccup; who is obviously terrified, and that doesn't sit well with loki. not with his old!self's echoes still ruining his relationships in this life too. ]

I'm really not going to hurt you, you can stop jittering about.