'The Winter of the World' - Michael Scott Rohan (A Quick Plug!)

'The Anvil of Ice'
'The Forge in the Forest'
'The Hammer of the Sun'

You don't really see these books much in bookstores nowadays but if you happen to come across them (in a second hand bookshop) then pick them up straight away. This first trilogy in the 'Winter of the World' series is well worth a look.
The series is set in a world, not unlike our own, that is encroached upon by relentless walls of ice (driven by 'Powers' that hate the filth of humanity). Our hero, 'Alv', is born into this world as a farmhand but by the end will find himself standing side by side with royalty. You're probably thinking that you've heard this one before but you'd be wrong. Alv has a gift for smithcraft and although there is a 'destiny' involved (that goes far beyond mere royalty), his real quest is to put right the wrongs that his smithcraft causes right at the very beginning of the first book.
There are some tedious descriptions of smithcraft but get through them and you'll be rewarded with a series that foreshadows authors such as Brian Ruckley and J.V.Jones. Even now when I read this series, I'm still surprised by the twists and turns that Rohan employs. The ending is a real shocker and a lot of things suddenly make sense. A richly drawn world that is only rivalled by the superb Ian Miller artwork on the covers. Anyone who is a fantasy fan should pick these up if they haven't already.
There is another (looser) trilogy that comes after this one, more on that another time.