Luis Marqueli Bontempo (Savona, January 1, 1740 – Santa Cruz de Tenerife, December 16, 1817) was the Italian officer whose courage and clearheadedness turned the tide of the “Deed of July 25” in 1797—the heroic defense of Santa Cruz de Tenerife against Horatio Nelson’s British fleet. Then a colonel in the Corps of Engineers, Marqueli played a decisive role in persuading General Antonio Gutiérrez de Otero to refuse a British ultimatum demanding surrender, thereby ensuring the city’s and the island’s survival.
During the assault, which began with Nelson’s landing on July 22, the Spanish troops faced fierce fighting on multiple fronts; on the night of July 24–25, the Castle of San Cristóbal was isolated and confusion among the officers reached its peak. Lieutenant Colonel Marqueli—a veteran of the Seven Years’ War and the Great Siege of Gibraltar in 1779—despite his frail health and advanced age, remained calm when many were overcome by despair.
When a British sergeant delivered an ultimatum to General Gutiérrez threatening to raze the city and massacre civilians if they refused, several dignitaries voiced fears of surrender. Marqueli intervened firmly, urging them not to give in to the threat and to persevere in the defense. At the critical moment, Lieutenant Vicente Siera arrived with five British prisoners and the news that the Canary Islands Infantry Battalion—previously presumed lost—was safe and would soon reinforce Santa Cruz. With the rough humor and colorful language typical of his Cuban background, Siera mocked the pessimists as “cowards” and “bastards,” provoking a liberating laugh among those present and bolstering the defenders’ morale.
Revived in spirit and heeding Marqueli’s counsel, General Gutiérrez ordered the ultimatum rejected and the release of the British sergeant, tasked with reporting Spain’s firm decision to his commander. In the subsequent battle, Nelson—severely wounded and having lost an arm—was forced to sign an unconditional surrender: he formally pledged never to attack the Canaries again, a vow he honored until his death at Trafalgar in 1805.
Marqueli’s contribution was immediately recognized by the Spanish authorities: in 1798 he became Chief Director of the Corps of Engineers, in 1802 Brigadier General, and in 1805 Field Marshal, while continuing to serve in Santa Cruz. Despite these honors, his career was marred by disputes with the Supreme Junta in Seville and by ongoing health problems: in 1815, at the age of seventy-five, he petitioned the king for promotion to Lieutenant General to secure a dignified pension for his wife and daughters.
Marqueli died on December 16, 1817; the General Commander of the Canaries commemorated him in a brief, solemn dispatch to the Minister of War. Today his memory is preserved in the Military History Museum of Santa Cruz de Tenerife: a posthumous portrait painted in 1849—based on a youthful miniature and his daughter’s descriptions—preserves his image in old age. A reserved man who shunned self-praise, Marqueli is revered as an exemplar of honor, loyalty, and wisdom—the one who, with steadfast resolve and intelligence, saved Santa Cruz from capitulation.