Armand de Gontaut, Baron of Biron (French pronunciation: [aʁmɑ̃ də ɡɔ̃to], 1524 – 26 July 1592) was a soldier, diplomat and Marshal of France.

Beginning his service during the Italian Wars, Biron served in Italy under Marshal Brissac and Guise in 1557 before rising to command his own cavalry regiment.

Returning to France with the Peace of Cateau-Cambrésis he took up his duties in Guyenne, where he observed the deteriorating religious situation that was soon to devolve into the French Wars of Religion.

As the war dragged on he found himself increasingly involved in diplomatic efforts, meeting with Jeanne d'Albret repeatedly to talk terms.

With peace declared in August 1570 he continued his negotiations with Albret in the hopes of setting up a marriage between her son Navarre and Margaret of Valois.

In the wake of the Massacre of Saint Bartholomew he was tasked with reducing the well defended city of La Rochelle, commanding the artillery batteries he made limited progress over the following months, before Anjou oversaw peace negotiations so that he might depart for the Poland-Lithuanian Commonwealth.

A wound he received in his early years made him lame for life, and gave him the nickname Armand Le Boiteux (the limper).

[4] He reported back to the crown in April 1564 that both the commissioners and those who desired to lodge complaints about the enforcement were being intimidated by the local nobility.

[13] With the marriage contract concluded, Biron arranged for the young Navarre's journey to Paris, and was with him when news of his mother's death arrived.

Negotiations continued until November, Biron and the crown remembering the difficulties the far less well defended city of Saint-Jean-d'Angély had presented, and desiring to avoid a siege.

By the time Anjou arrived in February, he had completed the investment of the town from land, but the harbour remained only partially closed, and no approach trenches had been dug.

Desertions ran rampant and by the time the outer wall was breached in June Anjou was increasingly tired of the siege.

[19] With Henri's return to France from Spain, he was keen to counteract the military influence that Retz had accrued as a favourite of Catherine in the proceeding years.

To prevent this, and allow the crown to focus on subduing Damville in Languedoc, Biron and the young Guise were sent out to monitor the frontier.

Navarre sent a contrite reply, but held several objections to the king's position, and another debate on the conseil privé erupted over whether to go to war.

[23] Navarre complained bitterly about Biron's role as lieutenant-general of Guyenne, bemoaning that he was governor in name only given how much authority his subordinate had.

[26] He took a brief leave in 1580 after he fell off a horse whilst campaigning at Toulouse, and while recovering appointed his son Charles to lead his forces.

[27] The king's younger brother Alençon seeking advancement accepted the offer from William the Silent to become sovereign of the United Provinces of the Netherlands in 1579, entering the country in 1582.

[31] With the death of Alençon the following year, Biron accompanied his body back to Paris for the lavish funeral overseen by Henri.

The two Marshals prosecuted the campaign half heartedly, and only the forces directly loyal to the Ligue under Mercœur conducted the war with any vigour.

Henri announced to the assembled nobles his desire to lead the French army out to destroy the invader, explaining it would allow him to regain authority from the Ligue.

Henri ordered the troops withdrawn to the Louvre, and tasked François d'O, Jean VI d'Aumont and Biron with leading them off the streets.

[36] With the assassination of Henri III outside Paris, Biron was among the marshals that recognised the legitimacy of Navarre as king immediately, and went over to support him in his fights with the Ligue.