Lloyds Bank plc is a British retail and commercial bank with branches across England and Wales. It has traditionally been considered one of the "Big Four" clearing banks. Lloyds Bank is the largest retail bank in Britain, and has an extensive network of branches and ATMs in England and Wales and offers 24-hour telephone and online banking services. As of 2012 it had 16 million personal customers and small business accounts. Founded in Birmingham in 1765, it expanded during the nineteenth and twentieth centuries and took over a number of smaller banking companies. In 1995 it merged with the Trustee Savings Bank and traded as Lloyds TSB Bank plc between 1999 and 2013. In January 2009, it became the principal subsidiary of Lloyds Banking Group, which was formed by the acquisition of HBOS by the then-Lloyds TSB Group. It has its operational headquarters in London and other offices in Wales and Scotland. It also operates a number of office complex, brand headquarters and data centres in Birmingham, Yorkshire including Leeds, Sheffield, Halifax and Wolverhampton.