A Spanish naval officer who helped prove the Earth is not a perfect sphere.

History · Published 3 October 2026 Swipe more like this →

In short: Antonio de Ulloa was a polymath whose career spanned scientific discovery, colonial administration, and naval warfare. From identifying platinum to witnessing rare optical phenomena in the Andes, his life was defined by Enlightenment inquiry and a persistent, often dangerous, struggle against the deep-seated corruption of the Spanish Empire.

Born in Seville in 1716, Ulloa joined the French Geodesic Mission to the Equator at nineteen. Tasked with measuring the meridian arc near Quito, he and his colleagues gathered data that confirmed the planet bulges at the equator and flattens at the poles, a finding that settled a major scientific dispute in favor of Newtonian physics. During this expedition, he also documented platinum, which he encountered while observing gold panning in present-day Colombia, and recorded the rare optical phenomenon now known as a glory or Brocken spectre.

Beyond his scientific contributions, Ulloa was a sharp critic of imperial governance. In a confidential report written with Jorge Juan around 1746, he detailed the systemic mismanagement and exploitation of Native populations by colonial officials and clergy. This document, published only in 1826 as 'Noticias secretas de América,' remains a foundational text in the study of institutional corruption. His later attempts to reform the mercury mines in Huancavelica were met with such fierce resistance from local elites that he described his tenure as a purgatory of constant persecution.

Ulloa’s administrative career was marked by conflict. As the first governor of Spanish Louisiana in 1766, his efforts to reorganize trade policies triggered a revolt by French Creole merchants, leading to his expulsion from New Orleans in 1768. Despite these political setbacks and a later court-martial for alleged dereliction of duty during the American Revolution—from which he was acquitted in 1782—he remained a high-ranking naval officer until his death in 1795. Today, he is remembered as a pivotal figure of the Spanish Enlightenment.

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