i.e. Birthday Thaler, is the name given to a large silver coin struck in 1666 to commemorate the eighty-eighth birthday of August, Duke of Brunswick-Wolfenbuttel. The obverse shows a bust of the Duke in a wreath of laurel and the inscription FAVSTUM. IVSTITAE. ET. PACIS. CONSORTIVM.
Source: Frey's Dictionary (American Journal of Numismatics, Vol. 50, 1916)