While exiled, Oswald (604-642) spent part of his boyhood with the monks on Iona. He later became King of Northumbria and evangelized it. Cadwallon had killed Oswald’s brother, the king, after he attempted to negotiate peace. From Wiki:
Subsequently, Oswald, at the head of a small army . . . met Cadwallon in battle at Heavenfield . . . Before the battle, Oswald had a wooden cross erected; he knelt down, holding the cross in position until enough earth had been thrown in the hole to make it stand firm. He then prayed and asked his army to join in.
Adomnán in his Life of Saint Columba offers a longer account, which Abbot Ségéne had heard from Oswald himself. Oswald, he says, had a vision of Columba the night before the battle, in which he was told:
Be strong and act manfully. Behold, I will be with thee. This coming night go out from your camp into battle, for the Lord has granted me that at this time your foes shall be put to flight and Cadwallon your enemy shall be delivered into your hands and you shall return victorious after battle and reign happily.
Oswald described his vision to his council and all agreed that they would be baptised and accept Christianity after the battle. In the battle that followed, the British were routed despite their superior numbers; Cadwallon himself was killed.
Once king, Oswald requested a missionary bishop be sent to Northumbria. Oswald gave the island of Lindisfarne to Aidan as his episcopal see, and Aidan achieved great success in spreading the Christian faith; Bede mentions that Oswald acted as Aidan’s interpreter when the latter was preaching, since Aidan did not know English well and Oswald had learned Irish during his exile.
We thank You for the saints before us. May we too plant the cross in the battles of our daily lives and heaven come to the field of our existence. Amen.