In their drive to develop a new generation of big Humbers to take them into the Sixties, Rootes commissioned an all-new unit-construction shell, which was the very first to weR the Humber emblem.

For more than a year after its release in 1957,  the Series I Hawk double as the basis not just for a new generation of  Hawks but also as a new Super Snipe, with Humber finding themselves way behind schedule with the release of the next generation of  Super Snipes.

Never slow at blowing their own trumpet, Humber placarded the Series I Hawk as the largest car in production in the UK  at that time, although that record would not remain intact for too long, with  BMC's C-Series "Farina"  range of cars released not so long after.

The Humber Hawk Series I’s shell was a sturdy all-steel four-door saloon, with distinctive wraparound front and rear windows. 

Soon after the release of the saloon version, a five-door estate car followed, the first models released in October 1957.

In both the saloon and estate version of the Mark I Hawks, the result was a sturdy and spacious car,  with a distinct Mid- Atlantic look.

The Mark I Hawk engine was a 2267cc overhead-lye unit capable of generating rated at 73bhp carried forward from the previous Hawk, which mated to a four-speed column-change gearbox, although with no synchromesh on first.

 Laycock overdrive was optional, as was (until 1962) Borg Warner automatic transmission, while Drum brakes were standard.

Up until the end of the Fifties, Rootes managed to squeeze in another update of the Hawk the Series IA took over in October 1959, with different internal gear ratios.

The Mark I was the best selling version of all the Hawks with just over 15,000 sold in the close to two years that this model was in production.

Overall, the Mark I- VI series of Humber  Hawks could be classed as a commercial success, selling a total of 41,000 carsin all of its versions during the seven years that it was in production sold