Tom Wood told Dylan Hartley he would be with him every step of the way after the England skipper was handed the Saints captaincy.
Hartley has returned to the role that he relinquished two years ago - and the hooker has also extended his Saints contract, which was due to expire next summer.
Wood was the Northampton captain last season, having taken over from Lee Dickson, who led the team during the 2015/16 campaign.
But Jim Mallinder's men have endured two frustrating seasons since topping the Premiership table in 2015.
And it will be hoped that Hartley's return to the captaincy role will be the catalyst for a change in fortunes at Franklin's Gardens.
The 31-year-old has played a big part in helping England recover after a difficult 2015 Rugby World Cup campaign.
Hartley was appointed England skipper in January 2016 and has since steered his country to back to back Six Nations titles as well as series wins in Australia and Argentina.
He will be desperate to get Saints back to where they feel they belong, and Wood has pledged to do everything he can to assist Hartley in that mission.
"Congrats and good luck to @DylanHartley back in the captains arm band for @SaintsRugby lots of work to do and I'll be with u every step," Wood posted on Twitter.