A collection of historic postage stamps issued when Hawaii was a kingdom is expected to fetch at least $2 million at auction.

Renowned stamp collector William H. Gross is offering 77 items May 29 during the World Stamp Show at New York’s Javits Center.

The collection has “some of the most iconic rarities in Hawaiian philately,” said Charles Shreve, director of Robert A. Siegel Auction Galleries.

It contains 10 examples of rare Hawaiian Missionary stamps issued in 1851 — some unused, some canceled and on original envelopes, some containing letters.

A 13-cent unused Missionary in near-mint condition is expected to bring $50,000 to $75,000.

“There are only seven unused examples known, and this is by far the finest-quality example in existence” of that denomination, said Shreve.

The Missionaries, used primarily by missionary settlers, were Hawaii’s first postage stamps. They were issued in 2-, 5- and 13-cent denominations and printed on very thin paper called pelure, which Gross likened to toilet paper.

They were Hawaii’s only postage stamps until the Kamehameha III issue, named for the king, in 1853.

“The Missionaries are extremely rare; to collectors they’re iconic. … They talk of an earlier time and place, a remote and far-off outpost,” said Daniel Piazza, curator of the Smithsonian National Postal Museum in Washington.

Gross said in an interview that one of his favorite covers, or envelopes, in the sale is addressed to a New Bedford, Mass., company. It combines stamps from two countries — known in the philatelic world as “mixed franking.”

“It’s a striking piece because of the five 13-cent Kamehameha stamps in combination with five U.S. stamps — four 10-cent George Washington stamps and one 12-cent George Washington stamp. Visually it’s just stunning,” said Gross, a Wall Street money manager who lives in Newport Beach, Calif.

The cover also has five 5-cent provisional surcharge stamps — handwritten on the 13-cent denomination due to a shortage of 5-cent stamps in 1857. It’s regarded as the most outstanding U.S. and Hawaiian multiple-rate franking cover outside the Missionary issue, according to the catalog. Its presale estimate is $250,000 to $350,000.

The sale also has letters without postage stamps, used before the issuance of Missionary Stamps. The recipient paid the postage when picking up the letter at a post office.

One letter, written by a missionary to someone in Danbury, Conn., sheds light on the life of Pacific island missionaries.

“We are fed and clothed and have nought to think of but our precious children and the souls by whom we are surrounded,” he writes. The work will exert “a great influence for good, or for evil” upon the indigenous population. It’s estimated to fetch $2,000 to $3,000.

The auction proceeds will be divided between the Hawaii Foodbank and the postal museum in Washington, where a gallery is named after Gross. To date, he has sold nearly $25 million of his non-U.S. stamp collection to benefit charities.

Hawaii became a U.S. territory in 1898 and the 50th state in 1959.