They're not considered Hollywood royalty, but maybe that's because they've always chosen roles that make them seem like regular people.

Kirk Douglas and Michael Douglas bring intensity to the films they make. Now they go under the spotlight in The Douglas Dynasty: The E! True Hollywood Story.

For more than six decades, audiences have loved seeing the Douglas men perform, whether Kirk was entertaining them in classics like Spartacus and The Bad and the Beautiful or Michael was exhibiting his versatility in Wall Street, Fatal Attraction and Wonder Boys.

Learn why neither father nor son could make marriage work the first time around, and see how the absence of a father figure in their early lives affected them. Plus, through exclusive interviews with friends and family members, find out how their complicated relationship evolved over time.

Tune in to hear about Kirk's decade-long struggle to make a flopped play into a movie, and why Michael, who took over the project, refused to cast his father in the lead role.

And keep an eye on the future of the Douglas family, as Michael starts a second generation of children with fellow Oscar winner Catherine Zeta-Jones.

But first, click to see how this famous father and son stack up against each another.