Can Maxwells equations be written as one equation?

Maxwells equations are usually written as a system of four equations. I’ve read somewhere that when Maxwell first wrote out his equations they were as a system of twenty equations though I think managed to reduce them by using quaternions.

With differential forms they can be written as just two equations. I’ve read that with Geometric Algebra it’s possible to write them as just one equation.

Q. Is this claim true, and does it present any real advantages or is the unity achieved here a mere chimera?