The Mystery of the Plate of Brass: California’s Greatest Hoax and the Search for its Perpetrators

This book tells the story of the plate of brass found in Marin County, California, in the 1930s and for decades widely thought to be a relic of Francis Drake’s sixteenth-century visit. Technical analyses during the 1970s, however, showed the artifact to be a modern fake. But who made it, and for what purpose, and why was “California’s greatest hoax” not detected sooner? These are among the queries answered by the authors, based upon research by The Drake Navigators Guild (DNG; a group of historians and mariners who study Drake’s 1577– 1580 voyage) and James Spitze. Nautical historian and DNG President Edward Von der Porten had nearly finished the manuscript when he died unexpectedly in 2018; his son, Michael, then saw to its publication. When Francis Drake boldly sailed through the Strait of Magellan and up the west coast of South America in 1579, he left in his wake looted Spanish ships and towns along with hostile mariners and colonists who deemed him a pirate. In fact, Drake was a privateer whose circumnavigation of the globe had been secretly sponsored by Queen Elizabeth and other English investors. This is why, before leaving the California harbor where he careened and re-provisioned his ship, Golden Hind, Drake affixed to a post an engraved brass plate declaring that the local (indigenous) “king and people” had freely relinquished their province to Her Majesty. Drake called this province Nova Albion (Albion being the old Roman name for England). Thus, in 1579 Drake laid claim on behalf of Elizabeth to America’s first New England, six years before English settlers arrived at Roanoke Island and 28 years before Jamestown was occupied. In 1936, Beryle Shinn found a rectangular plate of brass, inscribed and signed “... FRANCIS DRAKE”, at Greenbrae on the northwest shore of San Francisco Bay. This find was announced in April 1937 by Herbert Bolton, an eminent professor of history at the University of California, Berkeley (UCB). Soon afterwards, William Caldeira came forward to say that he had found the very same plate in 1933 near Drakes Bay and later discarded it at Greenbrae. Bolton judged the plate authentic, and metallurgical testing in 1937–1938 seemed confirmatory. Although some scholars expressed doubts, and rumors of a hoax were bruited, the general consensus over the next few decades was that the plate of brass was genuine. Its “discovery” fueled controversy as to where Drake had landed and was used by some to support a San Francisco Bay location. Meanwhile, in March 1937, the president of the California Historical Society (CHS) purchased the plate from Shinn for $3,500 and donated it to UCB.