sentences:  Diego Ribeiro, who entered Spanish service in 1518, prepared several versions of the chart, during 1525 to 1532, after Ferdinand Magellan's circumnavigation of the globe or after Spanish explorations in North America.Other revisions to the royal chart were directed by royal chartmakers Alonso de Chaves during 1536 and by Alonzo de Santa Cruz in 1542.Almost none of these maps have survived, but there were occasionally copies made for foreign princes and dignitaries, and some of them still exist.