Love Among the Ruins by Warwick Deeping

So Fulviac with his host passed northwards from Gambrevault, leaving Colgran and his ten thousand to guard the trenches. Flavian saw the black columns curl away over the green slopes, their pikes glittering against the blue fringe of the horizon, their banners blowing to the breeze. The red pavilion stood no longer in the meadows; the man on the black horse rode no more behind the barricades. Ominous was the marching of the host over the hills, a prophecy of many battles before the King's men could succour Gambrevault.

The gate-house stood in ruins, a shattered pile of masonry barriering the causeway from the meadows. The outer curtain wall on the north had been pierced between two towers; the stone-work crumbled fast, opening a gradual breach to the rebel sea dammed behind the trenches. The battlements were rent and ruinous; many a turret gaped and tottered. Still the bombards thundered, hurling their salvos of shot against the place, belching flame even through the night, while the arms of the great slings toiled like giant hands in the dark.