The 2nd chapter of Matthew tells us of an unspecified number (not necessarily three) of Magi (also translated as Wise men), who came to worship the young child (not newborn baby) Jesus in a house (not the manger).
That's why when King Herod found out the Magi didn't report back to him, he didn't just have all the male newborns killed, he had all the male children under the age of two killed.
The Bible also never mentions that the wise men were kings of any sort, this was an assumption made in later Christian writings.