On August 16, 1583 the Field Master of the Tercio in which Juan de Águila served, died in Dendermonde.
Ten days later, Farnese named him Field Master, at only 38 years old.

At the end of 1584 Siege of Antwerp began, in which Juan de Águila and his Tercio particularly distinguished themselves by defeating the Dutch who tried to rescue the city from the Covenstein dyke (May 27, 1585).
After the capture of the city in the summer of that year, the Tercios received their back pay: 37 overdue salaries from July 1582.

After taking Antwerp, Farnese graduated a part of the army and sent the rest to the north to help reimpose Catholicism and Spanish rule in the northern Netherlands.
The army commanded by Ernesto de Mansfeld consisted of three Tercios, including that of Juan del Águila.
On reaching the river Meuse, in late November, Mansfeld divided the army, some camped on the shore and another on the island of Bommel, formed by the rivers Meuse and Waal.
In this second group were the masters Juan del Águila and Francisco Arias de Bobadilla.

The Dutch rebels then broke the levees protecting the area, the water level rose and flooded the island.
The Spanish were thus isolated and unprotected in the Empel dam.
On December 2, a Dutch fleet entered the flooded land with the intention of annihilating the tercios.
With the artillery that they had managed to salvage, the troops of Juan del Águila occupied an islet that had formed after the flood and staved off the rebel boats to prevent them from approaching.
Meanwhile, the Dutch seized other islets and began construction of fortifications, which ended in record time despite the Spanish cannon shots.

Mansfeld got a few barges from the inhabitants of Den Bosch to attack the enemy fleet, but they were destroyed in a surprise attack.
The situation was desperate.

On the night of December 7 a soldier found, buried near the church of Empel, a table with the image of the Immaculada and, as December 8 was its feastday, the discovery was considered a good omen:
This very rich treasure that they discovered under the earth was a divine proclamation of good fortunes, and through the intercession of the Virgin Mary, they were waiting the blessed day
That same night, Bobadilla ordered an assault on the forts with the few boats available.
Meanwhile, the temperature dropped sharply and a strong wind began to blow.
The water then began to freeze.
As a result of this the Dutch ships were withdrawn for fear of being blocked and the Spanish were able to take the forts.

This unthinkable situation was thereafter referred to as the Miracle of Empel (in Dutch: Het Wonder van Empel).
The rebels exclaimed "God has become a Spaniard" and from then on the infantry began to devote itself to the Immaculada which led to her become its patron saint.

On January 24, 1586, Don Juan D'Aguila and his troops, including 17 foot soldiers and 4 Cornet cavalry horsemen, raided the German villages of Boslar, Muntz and Gevenich.
They gravely wounded many citizens, and stole their possessions or destroyed them.

Later in 1586, Juan del Águila's Tercio participated in the conquests of Grave (June 6), Neuss (July 26), Alpen (13 August) and the rescue of Zutphen (September 22), forcing the English army that had besieged it to lift the siege.

On June 12, 1587 the siege of the Esclusa began at the mouth of the Scheldt river.
In July Juan del Águila was seriously wounded.
Before completing his recovery he was called to the Court, where he arrived in the spring of 1588.
There, he was presented to Philip II with these words: "Your Majesty, meet a man born without fear."

The king assigned him a newly created tercio which was waiting in Santander.
The troops were part of the second landing army from the campaign against England.
In September, the operation was canceled when the Great Armada disaster occurred.
On August 16, 1583 the Field Master of the Tercio in which Juan de Águila served, died in Dendermonde. Ten days later, Farnese named him Field Master, at only 38 years old.
At the end of 1584 Siege of Antwerp began, in which Juan de Águila and his Tercio particularly distinguished themselves by defeating the Dutch who tried to rescue the city from the Covenstein dyke (May 27, 1585). After the capture of the city in the summer of that year, the Tercios received their back pay: 37 overdue salaries from July 1582.
After taking Antwerp, Farnese graduated a part of the army and sent the rest to the north to help reimpose Catholicism and Spanish rule in the northern Netherlands. The army commanded by Ernesto de Mansfeld consisted of three Tercios, including that of Juan del Águila. On reaching the river Meuse, in late November, Mansfeld divided the army, some camped on the shore and another on the island of Bommel, formed by the rivers Meuse and Waal. In this second group were the masters Juan del Águila and Francisco Arias de Bobadilla.
The Dutch rebels then broke the levees protecting the area, the water level rose and flooded the island. The Spanish were thus isolated and unprotected in the Empel dam. On December 2, a Dutch fleet entered the flooded land with the intention of annihilating the tercios. With the artillery that they had managed to salvage, the troops of Juan del Águila occupied an islet that had formed after the flood and staved off the rebel boats to prevent them from approaching. Meanwhile, the Dutch seized other islets and began construction of fortifications, which ended in record time despite the Spanish cannon shots.
Mansfeld got a few barges from the inhabitants of Den Bosch to attack the enemy fleet, but they were destroyed in a surprise attack. The situation was desperate.
On the night of December 7 a soldier found, buried near the church of Empel, a table with the image of the Immaculada and, as December 8 was its feastday, the discovery was considered a good omen:
This very rich treasure that they discovered under the earth was a divine proclamation of good fortunes, and through the intercession of the Virgin Mary, they were waiting the blessed day
That same night, Bobadilla ordered an assault on the forts with the few boats available. Meanwhile, the temperature dropped sharply and a strong wind began to blow. The water then began to freeze. As a result of this the Dutch ships were withdrawn for fear of being blocked and the Spanish were able to take the forts.
This unthinkable situation was thereafter referred to as the Miracle of Empel (in Dutch: Het Wonder van Empel). The rebels exclaimed "God has become a Spaniard" and from then on the infantry began to devote itself to the Immaculada which led to her become its patron saint.
On January 24, 1586, Don Juan D'Aguila and his troops, including 17 foot soldiers and 4 Cornet cavalry horsemen, raided the German villages of Boslar, Muntz and Gevenich. They gravely wounded many citizens, and stole their possessions or destroyed them. 
Later in 1586, Juan del Águila's Tercio participated in the conquests of Grave (June 6), Neuss (July 26), Alpen (13 August) and the rescue of Zutphen (September 22), forcing the English army that had besieged it to lift the siege.
On June 12, 1587 the siege of the Esclusa began at the mouth of the Scheldt river. In July Juan del Águila was seriously wounded. Before completing his recovery he was called to the Court, where he arrived in the spring of 1588. There, he was presented to Philip II with these words: "Your Majesty, meet a man born without fear."
The king assigned him a newly created tercio which was waiting in Santander. The troops were part of the second landing army from the campaign against England. In September, the operation was canceled when the Great Armada disaster occurred.
Juan del Águila