His public espousal of Zionism was simply a significant episode at that time three decades later when Mr Balfour was dead it was to have consequences as fateful as Mr Balfours own aberration

What is the correctly punctuated version of this sentence?
His public espousal of Zionism was simply a significant episode at that time; three decades later, when Mr. Balfour was dead, it was to have consequences as fateful as Mr. Balfour's own aberration.