The Thousand Orcs

The Thousand Orcs is first book of The Hunter's Blade Trilogy by R.A. Salvatore.

"''One dark elf. Two enchanted blades. One unknown enemy. And a horde of invaders.

It's been a long time since Drizzt Do'Urden has had to fight alone. When a ravaging mob of vicious orcs overruns the North and his friends are washed away in its evil tide, he must take matters into his own deadly hands."

Possible discrepancies
The book states on p. 291 that "Shallows was larger than Clicking Heels", but p. 257 gives the population of Shallows as "more than a hundred" (assumed to be no more than two hundred, otherwise it would have been given as such), while p. 50 refers to "the two hundred sturdy folk" of Clicking Heels. It could simply be that "larger" is intended to mean land area, however.