St Leger served in Ireland during Lord Deputy Essex's failed campaign.
He was one of six royalist witnesses present at a riverside conference with Irish confederates on 7 September 1599.
11 March] 1600,[4] near Cork, in a skirmish with Gaelic chieftain Hugh Maguire.
St Leger shot Maguire as he approached, though Maguire thrust his lance into St Leger's skull before succumbing to his gunshot wound.
[5][6][7] On 31 March 1600, Thomas Denham wrote to Cecil that St Leger's widow "is now preparing herself for the Court, to be a suitor".