Former Plaid Cymru leader Ieuan Wyn Jones is seeking to return to Westminster as the MP for Ynys Mon.
He represented the island in the Commons from 1987 to 2001, and in the Welsh Assembly from 1999 to 2013.
Mr Jones - a former deputy first minister of Wales - is one of five contenders for Plaid Cymru's nomination for the seat at the election in June.
Labour's sitting MP Albert Owen will be defending a majority of 229. The Tories held the seat from 1979 to 1987.
Also hoping to win the Plaid Cymru nomination are Ann Griffith, Dyfrig Jones, Elliott Riley-Walsh and Vaughan Williams.
John Rowlands, who fought the seat for Plaid in 2015, and Iwan Huws had also submitted their names before the deadline of midnight on Sunday but both have since withdrawn.
Local hustings are due to take place on Wednesday.
Mr Jones first fought Ynys Mon in 1983, when he came second to incumbent Conservative MP Keith Best, winning the seat at the second attempt in 1987.
He won again in 1992 and 1997, but stepped down at the 2001 general election to devote his energies to the Welsh Assembly, to which he had been elected in 1999.
Mr Jones succeeded Dafydd Wigley as leader of Plaid Cymru in 2000 and served as deputy first minister in a Labour/Plaid coalition Welsh Government from 2007 to 2011.
But following a disappointing 2011 election which saw the party lose seats and power, he resigned as leader, with Leanne Wood elected as his successor.
Mr Jones stood down from the assembly in 2013 to lead the Menai Business Park.
Ynys Mon will be one of Plaid Cymru's prime targets for the general election.
Following the 2015 election, the party's former parliamentary leader Elfyn Llwyd said it was "disappointing" the party had failed to add to its three Westminster seats.
Albert Owen, who has held Ynys Mon for Labour since 2001, has said he will defend the seat again in June.
A full list of candidates will be available after nominations close on 11 May.
Analysis by Nick Servini, BBC Wales political editor
Ieuan Wyn Jones's decision has come as a surprise to some who felt the former deputy first minister had retired from frontline politics.
It can also be seen in the context of a short, unexpected general election campaign in which all of the parties will want tried and tested political figures to fight marginal seats.
There will not be the time for less well-known personalities to build a profile.
Behind the scenes, there is a last-minute scramble underway to find suitable candidates by all of the parties.
All have an official selection process, but much of it is being fast tracked when time is of the essence, and one more day without an official candidate will be considered another day wasted.