Trpimir I, the founder of the Trpimirović dynasty of Croatia, issued a document that contains the first known use of the name Croats.

Trpimir I was a duke in Croatia from around 845 until his death in 864. He is considered the founder of the Trpimirović dynasty that ruled in Croatia, with interruptions, from around 845 until 1091. Although he was formally vassal of the Frankish Emperor Lothair I, Trpimir used Frankish-Byzantine conflicts to rule on his own.

The Trpimirović dynasty was a native Croatian dynasty that ruled in the Duchy and later the Kingdom of Croatia, with interruptions by the Domagojević dynasty from 845 until 1091. It was named after Trpimir I, the first member and founder. The most prominent rulers of the Trpimirović Dynasty include Tomislav, Petar Krešimir IV and Demetrius Zvonimir. The house gave four dukes, thirteen kings and a queen.

The Croats are a South Slavic ethnic group native to Croatia, Bosnia and Herzegovina and other neighboring countries in Central and Southeastern Europe who share a common Croatian ancestry, culture, history and language. They also form a sizeable minority in several neighboring countries, namely Slovenia, Austria, the Czech Republic, Germany, Hungary, Italy, Montenegro, Romania, Serbia and Slovakia.