The 55c stamp is from 2009 Christmas issue depicting House of Blackheads in Riga.
House of Blackheads is an important centre for public life and one of the main sights in Riga.It was first mentioned by sources in 1334 as the New House of the Large Guild and it is located near the Town Hall Square (Rātslaukums). The building was erected by the city itself, and originally it was rented to the merchants of the Large Guild and the unmarried merchants, the Brotherhood of Blackheads, who later, in 1713, purchased the building and became its proprietors.
The Blackheads was characteristically a common union of young, unmarried merchants and ship captains in the Hansa cities, which chose St. Maurice to be their patron. St. Mauritius was an imaginary African black moor (from this the name of the brotherhood “the Blackheads” comes). Due to their exceptional status the Blackheads played an important role in the society life and traditions; many VIPs of that time (including Russian tsars) took part in events organized by the Blackheads. As a German merchant club the Brotherhood of Blackheads existed in Riga until 1939.
ps: I sent a cover to you today,Oleg :)