He arrived in France in the same year, as a member of the Trás os Montes Brigade of the 2nd Infantry Division of the Expeditionary Corps.

The division saw no major battles, but suffered many casualties and extreme fatigue among the front-line soldiers from consecutive night raids.

[1][2] He found himself in the midst of the battle, in the field of Isberg, covering the withdrawal of Portuguese and Scots soldiers.

Finally, the Germans decided to go around his position, and Milhais found himself alone in the rear of the enemy lines for three days.

On the third day, Milhais, still carrying his Lewis gun, rescued a Scottish major from a swamp, and the two reached Allied lines.

[1] A few months later, Milhais once again held back a German assault single-handed with his Lewis gun, allowing a Belgian unit to retreat safely to a secondary trench without casualties.

When the Portuguese living there realized that Milhais was in need, the community gathered funds to send him back to Portugal with enough money to provide for his family.