A letter signed by Junipero Serra (1713-1784), who will become the first Hispanic saint to be canonised, on September 23, is up for auction at Bonhams.
The lot will cross the block in a sale of fine books and manuscripts in New York later today with a valuation of $60,000-90,000.
The Franciscan administrator Pangua wrote it in 1775. In it he lays out the ground rules for the leaders of five California missions under his control. Serra is one of four mission leaders to sign it.
Bonhams explains: "The first Alta California mission was established in 1769 by Junipero Serra.
"By early 1775, just 6 years after the founding of Mission San Diego, the Spanish had established five fully operational missions from San Diego to Monterey, laying the framework for what would ultimately be a series of 21 mission outposts designed to spread Christianity to the Native peoples and lay the groundwork for colonization."
Serra is a controversial figure today, blamed for spearheading the suppression of native religions and forcing thousands into slavery.
The sale also features Franz Kafka's passport, which carries an estimate of $10,000-15,000.
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