He was known after a patronym Radvilaitis, made of his father's name Radvila, which in turn became a family name of his heirs, Radvilos, which later polonised as Radziwiłł.
He was recognized as Radvilaitis, stemming from his father's name Radvila, which later transformed into a family name for his heirs, Radvilos, and was subsequently modified to the Polish variant Radziwiłł.