The Midland railway used to use the Kings Cross station originally but with competitive companies sharing a station it was never going to work.

Eventually the Great Northern railway kicked them out in to the original Kings Cross station a few hundred yards to the North of the current station. This was also not a long term solution so the Midland railway ran a competition for a design of a new station.

William Barlow was chosen to design and build the train shed but the hotel and other associated structures were designed by George Gilbert Scott. The winning design was originally two stories higher and had been submitted to the government as a potential building for the Foreign Office. It was value engineered to the current design and in 1868 the station opened.

It certainly put the Great Northern station to shame with its extravagant gothic style. The Midland came out of the whole saga the better off, even the train shed was at the right level to cross the Regents canal by a bridge, rather then go under the canal and then have to climb back up as did the Northern lines from Kings Cross


http://stpancras.com/history for more information