Robyn Hood: The Rise of Nottingham's Shadow.. Robyn Hood, #1

Over three centuries had passed since the cataclysmic event that had reshaped the world, reducing it to a mere shadow of its former self. Civilisations had crumbled, their towering achievements reduced to ruins and dust. A chilling 350 years have passed since the world teetered on oblivion. A megalomaniacal tyrant, unleashed a catastrophic inferno upon the planet, nearly wiping the canvas of civilisation utterly clean.
Now, gazing upon the landscape of England, it's as though time itself has been spun backwards, transporting us not to the 24th century but rather to the echoing depths of the 12th century. The relics of progress and prosperity have crumbled into the annals of history. England was carved up into territories, each run by a warlord. These warlords were known as sheriffs. At first, their ascent bore certain benefits, offering a semblance of order in a world plunged into lawlessness.
The sheriffs carved pathways through the tangled wilderness, resurrecting town walls, reviving forgotten roads, and even reconstructing castles, albeit at a heavy toll upon the hitherto peaceful denizens of the land. But the more power they gained, the more they taxed the populus, and if, like Loxley, that could not pay these taxes, slavery was the outcome.