What was common in the development of the Czech Republic and Poland?

Poland:
The original nucleus of the state – the Union of the Glade tribes in the area of ​​the city of Gniezno
The time of the folding of the state – IX-X centuries
The title of ruler and its change – 1025 – king
Religion – Christianity in the Roman version.
Relations with the Holy Roman Empire – Complete submission to Rome

Czech Republic:
The original core of the state – After the collapse of Great Moravia, the tribes of the Czechs subjugated their Vlzetgg Neighboring tribes
State formation time – IX century
The title of ruler and its change – 1085 – king.
Religion – Christianity in the Roman version.
Relations with the Holy Roman Empire- As part of the empire, but retained a significant degree of independence.