Complex sentence: In the end the two sides met up on the banks of the Spey, whereupon Moray retired into a "great stronghold of bog and wood" where he could not be followed, as Buchan later offered Edward by way of excuse.
Split into simpler sentences: In the end the two sides met up on the banks of the Spey. Afterward, Moray retired into a "great stronghold of bog and wood" where he could not be followed, as Buchan later offered Edward by way of excuse.