In 1853 he founded the bank of Samuel Montagu & Co.[2] At first the company concentrated on the exchange of coins, bullion and the collection of foreign coupons.
[3] Montagu's commitment to Jewish causes included both initiatives aimed at improving the lot of Jews in England, and his participation in the proto-Zionist "Lovers of Zion" movement.
[5] Montagu's funding helped the Federation secure the services of distinguished rabbinical scholars such as Dr Mayer Lerner of Wurzheim in 1890 and the Maggid of Kamenitsk, Chaim Zundel Maccoby.
[8] As a Yiddish-speaker, Montagu was able to appeal to the many immigrants within his constituency on religious grounds, arguing in 1886 that he hoped "not a single Jew would vote Conservative".
[9] In September 1888, after the murder of Annie Chapman at the hands of an unknown man later called Jack the Ripper, Montagu tried to offer a reward of £100 for the discovery and conviction of the criminal.
[10] In 1893, on behalf of the English "Lovers of Zion", Montagu presented a petition in favour of Jewish colonisation in Palestine to the Secretary of State for Foreign Affairs.
In 1899, after the proposals were rejected, Montagu subsequently gave £10,000 (equivalent to £1421861 in 2024) towards LCC housing on the White Hart Lane estate, Tottenham.
[17] His eldest child, Henrietta, was known for improving children's education[18] whilst his daughter Lily helped to establish Liberal Judaism.
[17] He was succeeded in the baronetcy and barony by his eldest son, Louis Montagu, co-founder of the anti-Zionist League of British Jews.