Jean Mousnier de la Montagne (Johannes La Montagne) was born in France in 1596. His family was Protestant and moved to Holland where, in 1619, La Montagne enrolled as a medical student at the University of Leiden. Two years later, he signed a petition of the Leiden Huguenot families addressed to the British Ambassador at the Hague seeking permission to establish a Huguenot colony in Virginia. Permission was refused and Montagne then joined the 1623 expedition to the Amazon River and the coast of Guiana in search of a site for a Huguenot colony. He returned to Leiden in 1625 and resumed his medical studies, but a few years later, on 26 July 1629, sailed for the island of Tobago, a Dutch possession in the Windward Islands, northeast of Guiana. Returning to Holland, he completed his medical studies in 1636.
On 25 September 1636, Dr. Johannes de la Montagne sailed for New Netherland with his wife and three children on the ship the Rensselaerswyck, owned jointly by the patroon Kiliaen Van Rensselaer and by Gerard DeForest, a relative of La Montagne’s wife. La Montagne’s excellent education and natural abilities (he spoke Latin, French, Dutch, and English, and later, several of the Indian languages) made him a leader in the community of New Amsterdam, where he immediately set up business as a physician. His wife’s relative, Henry DeForest, died soon after arriving in New Amsterdam, and Dr. La Montagne took charge of the DeForest tobacco plantation in mid-Manhattan.
La Montagne served on the New Netherland Council and was First Councillor to both Director Willem Kieft and Director-General Pieter Stuyvesant. He was also Commander of the troops on Manhattan Island (1640-1656), a member of the 1653 popular convention to demand governmental reform in New Amsterdam, and a commissioner of fortifications of the city in 1654. He played an important role in several commissions set up to negotiate peace with the Indians. Johannes La Montagne was appointed Vice-Director of the colony in 1656, with special responsibility for Fort Orange (Albany) and Beverwyck. When New Netherland passed to the English, Dr. La Montagne signed an oath of loyalty to the Crown.
Johannes de la Montagne is believed to have died in 1670 in Ulster County, New York.