(A). A banker or moneylender, so called because the first bankers were from Lombardy, and set up in Lombard Street (London), in the Middle Ages. The business of lending money on pawns was carried on in England by Italian merchants or bankers as early at least as the reign of Richard I. By the 12 Edward I., a messuage was confirmed to these traders where Lombard Street now stands; but the trade was first recognised in law by James I. The name Lombard (according to Stow) is a contraction of Longobards. Among the richest of these Longobard merchants was the celebrated Medici family, from whose armorial bearings the insignia of three golden balls has been derived. The Lombard bankers exercised a monopoly in pawnbroking till the reign of Queen Elizabeth.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894