Missouri Encyclopedia logo

Pedro Joseph Piernas, the first Spanish lieutenant governor in St. Louis, occupied that post between 1770 and 1775. He was born in San Sebastian, Spain, in either 1728 or 1729 and came to Louisiana with Governor Antonio de Ulloa in 1766 as a captain in the Spanish army. The following year Ulloa sent Captain Francisco Ríu and a contingent of Spanish soldiers to the Illinois Country with instructions to build military fortifications at the junction of the Missouri and Mississippi Rivers. When trouble erupted at the outpost on the Missouri and some of Ríu’s men deserted, Ulloa named Piernas to replace Ríu as commandant of Upper Louisiana.

Ulloa dispatched Piernas to take charge of Fort Don Carlos, but late in 1768 rebels seeking to reinstate French authority in New Orleans forced Ulloa to flee to Cuba. Before Ulloa departed he sent new orders to Piernas, instructing him to withdraw from Upper Louisiana after delivering Fort Don Carlos to the former French commandant in St. Louis. Piernas reached the Missouri River installation in March 1769 only thirteen days before he received Ulloa’s directive to evacuate. He withdrew from the fort immediately but tarried in nearby St. Louis for nearly a month while attempting to settle disputed government accounts with local merchants. Piernas headed downriver in late April and arrived in New Orleans in May. He and his men sailed for Havana in July, the last Spanish soldiers to leave the province in the aftermath of the uprising.

The next year a military expedition headed by Lieutenant General Alejandro O’Reilly reestablished Spanish authority in Louisiana. After taking charge in New Orleans, O’Reilly solicited information about conditions in Upper Louisiana from Captain Piernas, who had returned from Cuba. Although Piernas had been in Upper Louisiana only briefly, his detailed report offered an optimistic assessment of the region’s potential. In early 1770 O’Reilly took steps to place Upper Louisiana under full Spanish control by appointing a lieutenant governor to direct operations in St. Louis. He selected Piernas for the newly created post and granted him broad powers for maintaining order, administering justice, regulating trade, and managing Indian affairs.

In New Orleans, Piernas had married Fecilite Robineau de Portneuf, and she joined him in St. Louis, where she gave birth to at least two children. After he assumed control in St. Louis in May 1770, the new lieutenant governor moved quickly to solidify popular support behind the Spanish regime. Among other things he allayed local anxieties by publicly affirming the land titles granted by his French predecessor.

Piernas also solicited advice from influential French residents, especially concerning the management of Indian affairs, a task that he quickly discovered commanded a disproportionate share of his time. Piernas was a quick learner. When the Indians initially misinterpreted his reserved and dignified bearing as a sign of unfriendliness, he wisely copied the French practices of feasting and giving gifts to help win them over.

Piernas found the Osage especially vexing. He favored trade sanctions for bringing errant tribes to terms but soon discovered the shortcomings of that strategy. When Piernas refused to send Spanish-­licensed traders to their villages, the Indians simply sought British replacements. In 1772 Canadian trader Jean Marie Ducharme secretly crossed the Mississippi and headed up the Missouri with merchandise for the Indian trade. Piernas learned of Ducharme’s illicit activities and dispatched a militia company, under the command of Pierre de Laclède, to capture the trading party and seize its goods. They managed to intercept the expedition, but Ducharme escaped his captors and fled to Canada. Even so, Piernas had acted decisively to uphold Spanish authority in the region.

By all accounts, during his five-year stint as Upper Louisiana’s lieutenant governor, Piernas proved a good soldier and a competent administrator who served his king well. On April 24, 1775, he relinquished control in St. Louis to his successor, Francisco Cruzat.

Piernas returned to New Orleans and was assigned to the headquarters staff, where he steadily advanced in rank. In subsequent years when the governor­-general was away from the capital, Piernas occasionally served as Louisiana’s acting governor. In 1785 he attained the rank of colonel and was named commander of the Louisiana Regiment, a fitting climax to a distinguished career in Spanish service. The date and place of his death are unknown.

This article was first published in Lawrence O. Christensen, William E. Foley, Gary R. Kremer, and Kenneth H. Winn, eds., Dictionary of Missouri Biography (Columbia: University of Missouri Press, 1999), and appears here by permission of the author and original publisher.

Further Reading

Cleary, Patricia. The World, the Flesh, and the Devil: A History of Colonial St. Louis. Columbia: University of Missouri Press, 2011.

Din, Gilbert C., and Abraham P. Nasatir. The Imperial Osages: Spanish-Indian Diplomacy in the Mississippi Valley. Norman: University of Oklahoma Press, 1983.

Foley, William E. The Genesis of Missouri: From Wilderness Outpost to Statehood. Columbia: University of Missouri Press, 1989.

Nasatir, Abraham P. “Ducharme’s Invasion of Missouri: An Incident in the Anglo-Spanish Rivalry for the Indian Trade of Upper Louisiana.” Missouri Historical Review 24, no. 1 (1929): 3–25.

Published July 14, 2020; Last updated July 8, 2023

Rights Statement

Creative Commons Attribution-NonCommerical-ShareAlike 4.0 International (CC BY-NC-SA 4.0)