- Grand Master de Vasconcellos was the oldest Grand Master ever to be elected.
- He distinguished himself for the courage and intelligence he displayed during the various embassies he was entrusted with.
- Before elected Grand Master, he held the position of Bailiff of Acre.
- He became gravely ill and died only six months after his election.
Born in 1543, Luis Mendes de Vasconcellos was a Portuguese knight from the Langue of Castile and Portugal.
He entered the Order at the age of 30 and held the position of Bailiff of Acre, having distinguished himself for the courage and intelligence he displayed during the various embassies he was entrusted with.
On September 17, 1622, de Vasconcellos was elected as Grand Master and convened the Council of the Order just five days after his election.
The oldest Grand Master ever to be elected, de Vasconcellos ruled the Order for only six months. Although his reign was brief, de Vasconcellos issued some important appointments within the Order. He nominated Fra’ Berndardino Zuniga as Bailiff of Negroponte, Fra’ Pedro de Vargas de Azevedo as Bailiff of Acre, Fra’ Jacques de Montagu, previously Ambassador of the Order to France, was given the responsibility of the Priory of Toulouse, while Fra’ Nicolo della Marra was appointed General of the Galleys.
The oldest Grand Master ever to be elected, de Vasconcellos ruled the Order for only six months.
The elderly Grand Master continued to enrich and embellish the Magistral Palace and formed a body of Guards to follow him in public ceremonies.
De Vasconcellos clashed with Bishop Fra’ Baldassare Cagliares over the building of a Bishop's Palace in Valletta and, despite his opposition, the Bishopric of Malta was transferred from Birgu to Valletta.
Soon after his election, de Vasconcellos became gravely ill and on his deathbed appointed Fra’ Luigi Mazzinghi, Prior of Capua, as his lieutenant. He died on March 7, 1623, and was buried in the crypt of St John's Conventual Church.