Here is a list of the Black Company Books in Order.
The Books of the North
The Black Company (1984)
From the blurb:
Some feel the Lady, newly risen from centuries in thrall, stands between humankind and evil. Some feel she is evil itself. The hard-bitten men of the Black Company take their pay and do what they must, burying their doubts with their dead.
Until the prophesy: The White Rose has been reborn, somewhere, to embody good once more. There must be a way for the Black Company to find her…
So begins one of the greatest fantasy epics of our age―Glen Cook’s Chronicles of the Black Company.