“Not Merlin, my lord, if you please,” Strange protested when Lord Wellington first hailed him by that name. Merlin, as Strange tried to explain, if indeed he ever existed, was quite the wrong kind of magician for him, or English magic, to be associated with. Wellington dismissed these objections with some impatience, while Major Grant looked on with his usual sardonic expression. It was rather hard to be looked down on by these gentlemen when it was his road they were riding on, Strange thought. He never knew whether Wellington was really ignorant of his proper name or whether it merely amused him to pretend to be so, but it did not signify: Wellington had determined to call him Merlin, and Merlin he became.
The army's magician was a very different character from Mr Norrell's pupil, and his magic was increasingly neither modern nor what Mr Norrell would have called respectable. It was Merlin who moved rivers and churches at Wellington's command, Merlin who raised dead Neapolitan soldiers for the benefit of the British Army so that Grant could interrogate them about Wellington's missing cannon.
Hardly anybody called him Mr Strange any more, and nobody called him Jonathan. Jonathan belonged to Arabella, whose letters never came. Jonathan would not have sought comfort in Grant's bed for his loneliness; it was Merlin who did that, one bleak night in November and for many nights thereafter, and Merlin whose name Grant spoke, even in the act. It was possible to do these things because Strange was no longer himself.
On 6th April 1814, the Emperor Napoleon Buonaparte abdicated. The war was over, and Jonathan Strange returned to England, leaving Merlin behind him, as he thought for ever.