20 Pounds Northern Bank - 175th Anniversary

Northern Bank's 175th anniversary fell in 1999, marking the bank's founding in 1824 — making it one of the older continuously operating commercial banks in Ireland, north or south. The commemorative £20 was a limited issue rather than a standard replacement for the circulating series, though it remained legal tender in Northern Ireland alongside the regular polymer-era notes from other local issuers.

Northern Bank was still privately held at this point, shortly before its acquisition by Danske Bank in 2005 — and five years before the infamous £26.5 million Belfast vault robbery in December 2004 forced a complete reissue of the bank's entire note range.