The roots of the United Synagogue can be traced back to 1835. This year saw the signing of the treaty between the Hambro', Great and New synagogues which centralised the distribution of aid to the poor affiliated to all three synagogues. The proposer of the treaty was Nathan Mayer Rothschild (1777-1836). Nathan served as warden of the Great Synagogue in 1818 along with his brother-in-law Solomon Cohen. He first proposed the idea in 1823 and hosted negotiations at New Court in 1824.
The first President of the United Synagogue on its establishment in 1870 was Anthony de Rothschild (1810-1876), Nathan's son. He remained President until his death in 1876. The presidency was then held by successive generations of the family: Nathaniel 'Natty', 1st Lord Rothschild (1840-1915) from 1876-1915, Leopold de Rothschild (1845-1917) from 1915-1917, and Lionel Nathan de Rothschild (1882-1942) from 1917-1942.