Which 1866 London bank failure helped trigger the Overend, Gurney crisis and a major stock-market panic?

The 1866 London bank failure that helped trigger the Overend, Gurney crisis was Overend, Gurney and Company.

Overend, Gurney and Company had grown from a bill-broking business into one of the most prominent financial institutions in Victorian Britain. It suspended payments on 10 May 1866 after suffering heavy losses from risky railway and infrastructure lending. The failure caused panic in London and led to a run on other banks and financial companies.

The Bank of England responded by requesting a suspension of the Bank Charter Act's restrictions, allowing it to expand emergency lending. The crisis helped establish the modern central-bank role of lender of last resort. Overend, Gurney's collapse is sometimes confused with later British banking crises involving Barings Bank, but Barings failed in 1890, more than two decades later. The 1866 panic also contributed to a broader European financial downturn.