WikiTimescale
Here's an interesting new twist. Markus Szumovski (Austria) has created Wiki software dedicated to timelines.

Now, this implementation is set up for broad world history. But you can install your own copy and cover and period or subject you want.

Meanwhile, customize the original Wiki. In particulr, switch to "People Only" mode. This switches off the labels and events and just lets you see who lived when. While you're there, add Phillip to Alexander's timespace.

The software has some basic work to do...the back button sends you to the start condition, and it's hard to tell how to navigate and zoom. But this makes for some interesting thinking.