The first Napoleonic decree of 1800 issued for Lomellina establishes that the Agogna department is divided into 17 districts, or municipal districts, Mede is the capital of the third district and Campalestro is part of it (law 11 brumale year IX).
With the decree of 25 Fiorile 1800 instead, considering that for the activation of the prefectures, vice-prefectures and related administrative bodies a new division of departments and districts was established, Campalestro is included in the second district of Vigevano, department of Agogna (Law 25 Fiorile year IX).
In the territorial subdivision of April 28, 1806, Campalestro falls within the Agogna department, district of Vigevano, fourth canton of Mede, as a third class municipality united with Vellezzo Terno and its Pieve, with a population of 496 inhabitants (subdivision 1806).
With the subdivision of 7 October 1814 Campalestro is included in the district of Mede and dependencies, in the province of Mortara (royal edict 1814, ASCVo).
With the royal edict of November 10, 1818, the number of municipalities was reduced from 125, as many as there were in the eighteenth century, to 71 and the provinces of Mortara and Vigevano were abolished, re-creating the Province of Lomellina, divided, in turn, into 14 districts ( royal edict 1818, ASC Casei Gerola).
Campalestro is today a hamlet of Vellezzo.