1600's porcelain plates

Possibly just a commemorative date, it's not uncommon for European plates to depict famous people, royalty etc. on the anniversary of their birth/death. The works of famous artists were popular decorative features on Continental porcelain throughout the 18th & 19th century. During the late 19th century there was also a fad for " China Decorating" as well, where hobbyists would hand paint blank porcelain plates. Because these pieces were not for commercial sale the artist often signed the plates any way they wanted to. There is only so much you can tell from images, you really need to have them checked out by an appraiser who can physically examine them. Lovejoy