The Castle of Burgos lies on an isolated hill which rises straight out of the streets of the north-western corner of that ancient city, and overtops them by 200 feet or rather more. Ere ever there were kings in Castile, it had been the residence of Fernan Gonzalez, and the early counts who recovered the land from the Moors. Rebuilt a dozen times in the Middle Ages, and long a favourite palace of the Castilian kings, it had been ruined by a great fire in 1736, and since then had not been inhabited. There only remained an empty shell, of which the most important part was the great Donjon which had defied the flames. The summit of the hill is only 250 yards long: the eastern section of it was occupied by the Donjon, the western by a large church, Santa Maria la Blanca: between them were more or less ruined buildings, which had suffered from the conflagration. Passing by Burgos in 1808, after the battle of Gamonal, Napoleon had noted the commanding situation of the hill, and had determined to make it one of the fortified bases upon which the French domination in northern Spain was to be founded. He had caused a plan to be drawn up for the conversion of the ruined mediaeval stronghold into a modern citadel, which should overawe the city below, and serve as a half-way house, an arsenal, and a dépôt for French troops moving between Bayonne and Madrid. Considered as a fortress it had one prominent defect: while its eastern, southern, and western sides look down into the low ground around the Arlanzon river, there lies on its northern side, only 300 yards away, a flat-topped plateau, called the hill of San Miguel, which rises to within a few feet of the same height as the Donjon, and overlooks all the lower slopes of the Castle mount. As this rising ground--now occupied by the city reservoir of Burgos--commanded so much of the defences, Napoleon held that it must be occupied, and a fort upon it formed part of his original plan. But the Emperor passed on; the tide of war swept far south of Madrid; and the full scheme for the fortification of Burgos was never carried out; money--the essential thing when building is in hand--was never forthcoming in sufficient quantities, and the actual state of the place in 1812 was very different from what it would have been if Napoleon’s orders had been carried out in detail. Enough was done to make the Castle impregnable against guerrillero bands--the only enemies who ever came near it between 1809 and 1812--but it could not be described as a complete or satisfactory piece of military engineering. Against a besieger unprovided with sufficient artillery it was formidable enough: round two-thirds of its circuit it had a complete double _enceinte_, enclosing the Donjon and the church on the summit which formed its nucleus. On the western side, for about one-third of its circumference, it had an outer or third line of defence, to take in the lowest slopes of the hill on which it lies.