Main altarpiece of the parish church of Santa María de Cáseda

We can consider this altarpiece as the cover letter of Juan de Anchieta in Navarre, since it was the first great machine that he contracted at the end of 1576 with the mayor, jurors and local neighbors. Following the design drawn up by the master, Pedro de Contreras, a carver who was prior of the brotherhood of San José and Santo Tomás of Pamplona, which grouped the woodworking trades, was in charge of its assembly. Built in the four-year deadline , it was appraised in 1581 by the Riojan Pedro de Arbulo, whom he had met in Astorga and Valladolid, and the church appointed Juan Rigalte, a resident of Zaragoza. The final price, after the estimate was appealed, was 4,200 ducats. It is not strange that more than two centuries had to pass, once the first painting was restored, before the work in white could receive its essential polychrome complement, so that the burnished gilding and the painting of "natural cloths" applied by Juan Martín de Andrés from 1778 onwards only disfigured the outlines of the carving. All this constructive history is collected in a monograph by M.ª T. Goyeneche in Príncipe de Viana.

The architectural concept has definitely prevailed here as opposed to the decorative concept of the Plateresque altarpieces. Its Michelangelesque mannerist design, inspired by the altarpiece of the cathedral of Astorga, sample, adapted to the octagonal chevet, an altarpiece-facade of great structural clarity with a outline of three sections and three streets. The division of the whole into parts is made by means of independent boxes or portadillas that decrease in height by virtue of the optical correction. To walk through this altarpiece is to be transported for a moment to the most famous works of Michelangelo's organic architecture in Florence and Rome, since its lexicon is formed by projecting boxes and recessed classical columns, pediments of various types with recumbent naked boys, the superimposition of two triumphal arches or serlianas in the central street, and decoration of garlands and pendants. At the ends of the bank there are two foliaceous mensulons with eagle heads.

A history of salvation unfolds here with a complete Marian program in the six reliefs of the side streets from the Annunciation to Pentecost and the carvings of the central street. There are some reliefs that have been placed, such as the Visitation that surprises us in the third section, something that must have happened by mistake during the reassembly of the 18th century after the polychromy of the altarpiece. It begins on the bench with the four Passion reliefs of the Supper, Fall of Christ and meeting with Veronica, Lamentation and Holy Burial. The figure of the dead Christ in these last two scenes derives from drawings by Michelangelo through an etching by Parmigianino and a study by Rosso Fiorentino. The manner in which Christ rests his head on his shoulder in the Burial is found in Michelangelo's Palestrina Pietà. Throughout the altarpiece there are replicas with "fierce expressions" of Michelangelo's Moses, such as the prophet in the attic, St. Paul, St. Joseph in the Adoration of the Shepherds or Joseph of Arimathea in the Holy Burial.

The Virgin of the Rosary is a Roman matron with similar characteristics to the Madonnas of Las Huelgas and Recoletas of Pamplona. The female models of Anchieta present profile Hellenic with the nose that continues the line of the forehead, tight lips, powerful neck and hair gathered with parted in the middle. The necklines of his tunics are usually bordered by a characteristic fan-shaped gathering and are fastened with leather bodices, like those of his referents Juan de Juni and Gaspar Becerra. Characteristic of the Basque master is the placement of a folded veil over the head, in the manner of Michelangelo's Madonna of Bruges, as García Gainza has rightly observed.

For the group of the Assumption, which is represented standing, bordered and crowned by angels, he chose the model with open arms in a declamatory attitude and heavenly gaze, which still reminds us of images by his master Juan de Juni, such as the titular Assumption of the altarpiece of the cathedral of Burgo de Osma. Although the twisting of the neck is similar, the rounded head with tight lips has replaced the longing expression of the Soria image. The Coronation of the Virgin is very similar to the one he made in 1578 for the altarpiece of the cathedral of Burgos, where Christ and God the Father flank her, being her Son with bare chest who crowns her, as in the altarpiece of Astorga. In Cáseda, as the niche that houses it has a vertical format, these figures are arranged in an upper register and the dove of the Holy Spirit is placed outside under the split pediment.

The tabernacle is an independent small temple of central plan with octagonal angles and similar facades on its three sides, in a beautiful example of biaxial symmetry. They are supported by paired Corinthian columns of Michelangelesque lineage that support triangular pediments with their concave vertex. The Institution of the Eucharist is represented in relief on the door, with two adoring angels in the lower part, topic that is repeated in the tabernacle of Añorbe. They lead to this door three steps that remind us of the stairs of access to the Roman temples. On it sits a second body, from which was removed an exhibitor with rear doors that had destroyed the central niche. After its restoration was placed in its place the Romanesque group of the Offering of the loaves of Abraham to Melchizedek, Eucharistic prefiguration of the Old Testament that will be repeated ten years later in the tabernacle of Santa Maria de Tafalla.