Memo Symons (commonly written Menno Simonis, and defined as "Menno, son of Simon;" but Symons was his surname), a religious reformer, born at Witmarsum in West Friesland about 1496, died at Wtistenfelde, Ilolstein, Jan. 13, 1561. In 1524 he became a vicar at Pingjum, where he studied the Bible and preached repentance. In 1531, in the neighboring city of Leeuwarden, Sicke Snyder, an Anabaptist, was beheaded. This led Menno to examine the question of infant baptism, which he thereafter considered un-scriptural. Yet he accepted a call as curate of Witmarsum, and while he resided there a band of Anabaptists seized and fortified a cloister in the vicinity, but were captured and put to death (February, 1535). Menno's brother was among the slain, and he reproached himself for not having joined these brethren, in order to teach them better. Renouncing the Roman Catholic church and the priesthood, and accepting a call to be the pastor of a few Anabaptists who never had been connected with the fanatical party, Menno began the life of an itinerant preacher, and with others organized numerous churches, principally in West Friesland. In 1543 persecution became so severe that he had to leave his native province. He first went to Cologne, where a flourishing church was gathered.

Driven from there in 1546, he travelled in Ilolstein, Mecklenburg, and Livonia, preaching and organizing churches. The last years of his life were embittered by dissensions among his adherents on the nature of ecclesiastical excommunication. The stricter party, led by Bouwens, insisted on total separation from an excommunicated person, even on the part of the wife. The milder party objected to this. Menno, to avoid excommunication, sided with the stricter party, a step which he afterward regretted. At Wiistenfelde, where he died, lie had liberty to print his books. His principal work is the "Fundamental Book on the saving Doctrine of Christ" (1539). His writings, all in Dutch, were first collected in 1600, then in 1646; the last and most complete edition was printed at Amsterdam in 1681. While he agreed with the Swiss Anabaptists on non-resistance and the unlawfulness of oaths, he held Luther's views on justification. From both he differed in believing that Christ did not take his flesh from Mary, but that a heavenly human nature passed through her as a channel. Feet washing as an ordinance was never taught by Menno. The mode of baptism is mentioned in his writings only once, and in such a way that it appears that he practised pouring.

The best biography of Menno is Het leven en de verrichtingen tan Menno Symons, by A. M. Cramer (Amsterdam, 1837). (See Anabaptists, and Mennonites).