Santa Ana de Pusa is the last town founded in the Sefiorio de Valdepusa, being its first founders Diego Garcia Lopez and Blas Muñoz in the 1522. These deceased, the Lord de Valdepusa, in 1524, founded a settlement and to be able to repopulate it, grants letter puebla October 16, 1526 to twenty-two residents of Magan, who called the place as "Santa Ana de Bienvenida".
Topographic relations of Felipe II's 1578 provide relevant data on the population:
"The first seems that they were two small villages the Canchar or scree and the other around the Hermitage of our Lady of welcome. The name of this place is that it is their church dedicated to Santa Ana and because before there was a Hermitage at half a League of the people dedicated to our Lady of welcome. It is a village of San Martín de Valdepusa. The Administration is in the hands of an ordinary mayor, an alderman and a Butler, with a jurisdiction over the lawsuits of 100 mrs, when they exceed that amount going to San Martin. It is land montosa, rough, with cliffs. "It's tired wood" of the Dehesa de Valdepusa, where there are deer. Runs to pair your term Brook Pusa. Lack their banks of orchards and nearly of fish. The village is lack of water. They will grind the Tagus River. His term is it's stretch, lacks pasta. At half a League to the West is the land of Talavera, villa which bring the most things and Santa Olalla; the salt comes from Las Espartinas (is rock salt). Because they are poor they may not bring Texas to their homes. The Church is small, it has built handouts from neighbors".