Dr. Nathan Marcus Adler, a.k.a. Hillel Nissim Adler, (ca.1800–1891), born in Hanover, was a Chief Rabbi of Britain 1845–1891, probably the most prominent 19th century rabbi in the English-speaking world. His distant relative Jacob Adler, who made his acquaintance in the winter of 1883–1884, described him as the "highest religious authority not only of London Jews but of all Orthodox Jews throughout Great Britain and the Empire." He subscribed to what was known as the Frankfurter Orthodoxy .

The first university-educated Chief Rabbi of Britain, and the first to undertake regular pastoral tours within the United Kingdom, he was also a founder of the National Society for the Prevention of Cruelty and Better Protection of Children. His period as Chief Rabbi saw the completion of the emancipation of Jews within the United Kingdom; the election (1847) and seating (1858) of Lionel de Rothschild as the first Jewish member of parliament; Nathan Mayer Rothschild's ascent as the first Jewish member of House of Lords (1885); and Sir David Salomons term as the first Jewish Lord Mayor of London (1855).

Adler was instrumental in bringing together the United Synagogue, established by Act of Parliament in 1870. As of 2005, this remains the largest religious grouping within the British Jewish community, and takes its religious authority from the Chief Rabbi.

London's Jewish Institute today stands on Adler Street, named after him. His son Hermann Marcus Adler was also a distinguished rabbi: head of a congregation in Bayswater during his father's lifetime, Adler's assistant from the time Adler's health began to deteriorate in 1879, and his successor as Chief Rabbi.

References

• Adler, Jacob, A Life on the Stage: A Memoir, translated and with commentary by Lulla Rosenfeld, Knopf, New York, 1999, ISBN 067941351. [Adler, 1999, 233-234]
• Nathan Marcus Adler on the official site of the Chief Rabbi of Britain.