An resume should include only the last ten years of experience.
Content of your resume should be selected strategically to support your focus and value proposition. While it is true that readers of your resume will be most interested in your most recent experience, there is often value in including experience further back in your history. Perhaps your early career includes work for well-known, prestigious companies. Perhaps you want to document the full scope of your cross-industry experience, much of which occurred in your early career. Perhaps you believe some valuable networking opportunities may come out of your experience 15 or 20 years ago. Or perhaps your most impressive accomplishments were in a position you held 12 years ago.
In any case, it will be apparent to the reader that your executive career did not suddenly materialize ten years ago so there is little harm and many benefits to summarizing this early experience. Of course, this does not mean that you must give equal page weight to your early career. If you feel early dates will be used to screen you out, subtly leave them out of your early career summary. If some early career positions have more strategic relevance than others, give them more emphasis in your summary. Think carefully about the content of your resume. If there is solid reasoning behind your desire to present early experience, than do so.
