Raiders smashed their way into Ribble Valley Borough Council's civic suite and escaped with mayoral chains estimated to cost over £15,000.
The break-in occurred in the early hours of Monday.
Among the items taken was a crafted from silver and enamelled gilt, have the following marks: Bowland Rural District Council – 66g and 74g badges engraved ‘I will lift up mine eyes’ and hallmarked 1966 London S&S Ltd, and 214g chain hallmarked 1961 London S&S Ltd; Rural District Council of Clitheroe – 146g badge engraved ‘Nostrum Est Rura Tueri’ and 270g chain hallmarked 1958 London S&S Ltd; Rural District Council of Blackburn – 102g badge engraved ‘Serva Fidem’ and 350g chain hallmarked 1954 London EB; and 270g badge and chain engraved ‘This regalia was presented in 1965 for the use of the Chairman’s Lady’ and hallmarked 1965 Birmingham Thomas Fatorrini.
Ribble Valley Borough Council chief executive, Marshal Scott, confirmed that the Ribble Valley Civic Suite was broken into.
He said: “The thieves smashed display cases and took five sets of mayoral chains and badges of office from the former Bowland, Clitheroe and Blackburn Rural District Councils.
“The items have a combined value of £15,250, but their historic value is significantly more and this theft constitutes the loss of important and unique civic artefacts.”
Police investigations are continuing into the theft and officers are studying CCTV footage of the inside of the civic suite.
Anyone with information is asked to contact the police in confidence on 101, quoting the log number: LC-20190610-0408.