Adrian Cox has been appointed as his replacement, having worked under Beazley for 20 years.
He has over 25 years of industry experience, most recently as the firm’s Chief Underwriting Officer.
“I am delighted to be appointed CEO of Beazley,” Cox said.
“I am excited about the opportunities ahead and the chance to build on our proven and successful business model in the years to come.”
Cox will take over on April 1 2021, after Horton’s term ends on March 31
The latter is expected to take up his new role at QBE after September 1 this year.
“I have every confidence in Adrian as my successor and believe he is the best person to lead the Company going forward,” Horton said.
“I am pleased to be leaving the Group in such capable hands and I wish Adrian and the whole Beazley team all the best for the future.”