The apostle's tomb soon became very important to the monarchy. This is clear from the many privileges and donations it received throughout history, including the Compostela Cross given as an offering by Alfonso III the Great in the year 827. It was stolen from the Chapel of Relics in 1906 and has never been recovered.
It was a "crux quadrata" or Greek Cross, which was very common type of cross in this period, modeled on the Galla Placidia Cross kept at Brescia Cathedral. It is in the style of the Oviedo Cross of the Angels, donated by Alfonso II the Chaste in 808.
Besides the references already cited, prints, phototypes, and photoengravings of the lost Compostela Cross have survived to the present day, allowing reproductions to be made. One example by silversmith Ricardo Martínez stands in place of the original on the new Altarpiece of Relics, which was created by Maximino Magariños after the fire of 1921 destroyed Bernardo Cabrera's mannerist altarpiece.