Ian Luder takes office today as the 681st Lord Mayor of the City of London, in advance of Saturday's Lord Mayor's Show.
The tax accountant and City businessman is a member of West London (Reform) Synagogue, where a "service of unity" to mark his election is being held today.
A Shabbat morning service will be staged at the Guildhall for Jews involved in the traditional Lord Mayor's procession through the streets of London. Both services will be conducted by Reform Judaism head Rabbi Tony Bayfield, whom Mr Luder has chosen as his chaplain.
"Not only have I been a member of the Reform movement all my life, but my family's connection with Rabbi Bayfield goes back a long way," Mr Luder said.