DDR - Wilhelm Pieck , in 1949, he became the first President of the German Democratic Republic
http://en.wikipedia.org/wiki/Wilhelm_PieckPostmark :
BERLIN W8 3.1.1959DDR - Walter Ulbricht , first secretary of the Socialist Unity Party, and as such the actual leader of East Germany, from 1950 to 1971. From President Wilhelm Pieck's death in 1960 he was also the East German head of state until his own death in 1973.
http://en.wikipedia.org/wiki/Walter_UlbrichtSpecial postmark :
BERLIN 1085 27.-6.68 WALTER ULBRICHT 75 JAHRE Another one and the last !
DDR - Erich Honecker , the General Secretary of the Socialist Unity Party, led East Germany from 1971 until the weeks preceding the fall of the Berlin Wall in 1989.
http://en.wikipedia.org/wiki/HoneckerSpecial postmark " 25 years Soviet Union - DDR friendship " :
BERLIN 1085 -4.-7.72p.s. I am not sure about the text of this postmark !