Sentence:  Born in the same day of the month and hour of the day with the Queen, but two years before her birth, the supposed <WSD>synastry</WSD> of their destinies might partly account, in that age of astrological superstition, for the influence which he perpetually exerted. 
Meaning of the word marked with <WSD> tags:  similarity of condition, fortune, etc., as prefigured by astrological calculation