- Nicolas Cotoner succeeded his brother, Rafael Cotoner, as Grand Master.
- He strengthened Malta's defenses by constructing the Cottonera Lines fortifications and Fort Ricasoli.
- He introduced windmills to Malta, generating revenue for the Order's Treasury.
- Amid a 1675 plague outbreak, he established the Chair of Anatomy and Surgery at Sacra Infermeria.
Born in 1608, Nicolas Cotoner y de Oleza, like his elder brother, had been Bailiff of Mallorca and had fought in the war of Venice-ruled Candia.
Succeeding his brother Rafael, Nicolas was elected Grand Master on October 23, 1663, and he wasted no time in making substantial contributions to the defense and development of Malta.
Anticipating a potential Turkish attack, Cotoner prioritized strengthening the island's defenses.
In anticipation of possible Turkish attacks, the Cottonera Lines and Fort Ricasoli were built.
With the help of Italian military engineer Antonio Maurizio Valperga, the impressive Cottonera Lines fortifications were built.
Fort Ricasoli was also constructed to protect the harbor entrance.
To celebrate these achievements, a grand archway was erected in Żabbar in 1675, adorned with the bust of the Grand Master himself.
Cotoner's influence extended beyond military prowess. He introduced windmills to Malta, initially constructing three in Floriana, Bormla, and Żebbug. These innovative structures generated revenue for the Order's Treasury, and future Grand Masters continued to build more across the island.
Cotoner was also dedicated to the spiritual welfare of the Aragonese knights. In 1674, he laid the foundation stone for the church of Our Lady of Pilar in Valletta, near the Auberge d'Aragon.
During his tenure, the Conventual Church of St. John (St. John’s Co-Cathedral) was further embellished, and Cotoner himself donated two sets of pontifical vestments featuring intricate embroidery and the Cotoner coat of arms.
He established the Chair of Anatomy and Surgery in Sacra Infermeria, improving medical knowledge during a plague outbreak.
Faced with a devastating plague outbreak in 1675, Cotoner took measures to improve medical knowledge on the island. In 1676, he established the Chair of Anatomy and Surgery within the Sacra Infermeria and appointed Maltese physician Fra’ Giuseppe Zammit as its first occupant.
Grand Master Nicolas Cotoner passed away on April 29, 1680, at the age of 75. His heart was returned to his birthplace, Mallorca, while his interior was interred at the Church of Our Lady of Victories in Valletta. His remains rest in the Chapel of Aragon in the Conventual Church, where a splendid mausoleum was erected in his honor.