Horses were the main means of land transport in the North. This continued into this century in Iceland. I'm not talking about stagecoaches, just plain horseback riding. Horses have plenty of loyalty and trust in them. They'll let you ride them to death or take them into danger.
Horses are a symbol of male sexuality.
The relationship between humans and horses is based on mutual trust and respect. This must be earned, for a gift looks for a gift, as the Havamal says. This should surprise no one as the horse is most associated with the God Ingvi Frey. Horses were carved into hillsides in Britain. Odin rides Sleipnir, the eight-legged horse.