Complex sentence: In 1997 TSR (and Gen Con) were acquired by Wizards of the Coast, which was then acquired by Hasbro, who in turn eventually sold Gen Con to the founder and former CEO of WotC, Peter Adkison, in 2002.
Split into simpler sentences: In 1997 TSR (and its owned property Gen Con) were acquired by Wizards of the Coast, which was then subsequently acquired by Hasbro. Hasbro then sold Gen Con to the founder and former CEO of Wizards of the Coast, Peter Adkison, in 2002.