In 2013 Ludwig Kasner received media attention in Poland and Germany after a new book shed light on Angela Merkel's family background.

[6][7][8] Ludwig Kasner was born out of wedlock to Ludwik Wojciechowski and Anna Kaźmierczak (1867–1943), ethnic Poles and citizens of the German Empire from Posen (now Poznań, Poland).

[10] After returning from war, in the aftermath of the Treaty of Versailles, Ludwig opted for German citizenship and relocated to Berlin, the hometown of his fiancée Marie Margarete Pörschke (August 11, 1905, at Berlin-Kreuzberg - November 9, 1986, at Berlin-Pankow).

[13] Ludwig Kasner was raised a Catholic, but in the 1930s the family converted to Lutheranism, and his son became a Protestant pastor.

Even before the 2013 media reports about Ludwig Kasner, Angela Merkel had said in 1995 that one of her grandfathers was originally from Poland; and in 2000 she had reiterated that she was one-quarter Polish.