St Albans Synagogue's change from affiliated status to full constituent United Synagogue membership was formally approved at Monday's US Council meeting.
Founded in 1933 by local residents who met in private houses, the congregation was boosted during World War II by people who fled London to escape the bombing. Many stayed on after the war, opening businesses in the city. St Albans affiliated to the US in 1948 and opened its purpose-built city centre synagogue in 1951.
"We are delighted to now be full members of the US family," said vice-chair Karen Appleby. "With their support, we are confident that our friendly community will continue to develop."