Blaeu was born at Uitgeest or Alkmaar. As the son of a well-to-do herring salesman, he was destined to succeed his father in the trade, but his interests lay more in Mathematics and Astronomy. Between 1594 and 1596 as a student of the Danish astronomer Tycho Brahe he qualified as an instrument and globe maker.[2] In 1600 he discovered the second ever variable star now known as P Cygni.