World Champion Lewis Hamilton brought the #1 back to Formula 1 during opening practice for the season-ending Abu Dhabi Grand Prix.
Since Formula 1 introduced permanent driver numbers in 2014 Hamilton has stuck with number 44, declining the option to run number 1 as is permitted for the World Champion.
The number 1 has not raced at a grand prix since the closing round of the 2014 campaign, when then reigning champion Sebastian Vettel last used it for Red Bull.
As in 2018, Hamilton took to the track during FP1 at the Yas Marina Circuit with number 1 on his Mercedes W10.
Hamilton is entered as number 44 and will sport it for the remainder of the weekend at the Yas Marina Circuit.