After the impressive demonstration of the City's technological and strategic during the brief and violent war it was unsurprising that the Empire would pull back and lick its wounds, expecting the city to advance the war to within its borders.
And the City did advance, but not as expected. Leaving the warmongering few preparing in their dust; traders, travellers and those looking for gainful employment soon ensured that the ties between the Empire and the City would lead if not to peace then to an uneasy truce.
Rumour has it that an ex-City dweller, a Dr. Van Telemann - within the Empire's governing body - was responsible for what many perceived as capitulation, with the empire turning away from the City and slowing its expansion plans considerably. Many other dimensions were grateful to claim alliance with the City, protecting them too from the Empire's expansion.
Over time the Empire continued to grow, using less aggressive tactics, negotiations of trade and alliance which served both the Empire and the City they now sometimes traded with.