Aggregate milestones from multiple projects into one timeline

Aggregate milestones from multiple projects into one timeline

We use high level milestones for each project. They come from a template, giving each project a uniform list of milestone definitions and task lists. Because we have many projects executing at the same time but in different phases management would like to see a consolidated timeline across all executing projects. 

Is there any way to accomplish this? In Microsoft Project I would do this by having a master project that would pull information from other project files.