McDonnell beat off stiff competition, including Paul Grimley and Michael McConville, to land the role.

Armagh won their 14th Ulster SFC crown under McDonnell's stewardship last year, but they exited the All-Ireland Championship this year when losing to Monaghan in the first round of the qualifiers.

The statement read: "Coiste Contae Ard Mhacha wish to announce that it has regrettably accepted the resignation of Peter McDonnell as Armagh senior football manager.

"Cathaoirleach Kevin Brady would like to take the opportunity to sincerely thank Peter on behalf of the entire county and pay tribute to him for his unquestionable commitment, passion for the county, and dedication to a very demanding post over the last two years.

"The support and application of his backroom team have also been second to none and have demonstrated the strong volunteer ethos in Armagh GAA."

Brady added: "Peter had shown tremendous conviction in accepting the role, given the challenge of the team's success in recent years, and the fact that a number of high profile and extremely talented players had also left the inter-county scene.

"This was a test that he met head on, and a number of new faces from his highly successful U-21 squad and from the county club scene were integrated comfortably to the panel.

"The winning of an Ulster Senior Championship in his first year could not be underestimated, and that Peter himself had been disappointed in not being able to build on this and reach the closing stages of the All-Ireland series.

"Peter himself is firmly of the opinion that despite the continuing transition period following the retirements of key players in recent months, the current senior panel is more than capable of competing for major honours, keeping the county among the highest echelon of teams, and considers that the county is fortunate to have such a talented and committed panel of players available.

"However, he feels after considerable deliberation that even at this stage of development he should step aside, and that the time is right for change at the helm of Armagh senior football."

The Mullaghbawn schoolteacher also managed the Armagh U-21s to a provincial title in 2007 and enjoyed stints managing Mullaghbawn, Armagh Harps, Down club Burren and Errigal Ciaran of Tyrone.