14.04.2016++++++++epa05258948 Vatican's Secretaty of State cardinal Pietro Parolin is seen during a mass to mark the 1,050th anniversary of Poland becoming a Christian nation at Royal Gniezno Cathedral in Gniezno, Poland, 14 April 2016. Mieszko I, the first ruler of the Polish state, accepted Christianity in 966.POLAND OUT - Bildfunk+++ Staatssekretär Seiner Heiligkeit +++(- Bildfunk+++ (c) picture-alliance/dpa/J. Kaczmarczyk