Rafael Bombelli feels that none of the works on algebra by the leading mathematicians of his day provide a careful and thorough exposition of the subject.

Instead of another convoluted treatise that only mathematicians could comprehend, the Bolognese-born mathematician decides to write a book on algebra that can be understood by anyone.

His text is to be be self-contained and easily read by those without higher education.

Bombelli treats cases involving imaginary roots in his L'Algebra, published in 1569.

He introduces the representative symbols +i and -i and describes how they both work.

Complex numbers, used by Bombelli in connection with the cubic, become gradually accepted about this time.

Bombelli dies in 1572 in Rome after being crushed by a large calf.