Simplify the following text for a Grade 10 native English-speaking person.
Original: Declaring himself now the Irish equivalent of King George V , he argued that as Irish head of state , in the absence of the British head of state from the negotiations , he too should not attend the peace conference called the Treaty Negotiations ( Octoberâ `` December 1921 ) at which British and Irish government leaders agreed to the effective independence of twenty-six of Ireland 's thirty-two counties as the Irish Free State , with Northern Ireland choosing to remain under British sovereignty .
Simplified: He said that as Irish head of state he would not go to the Treaty Negotiations of Octoberâ `` December 1921 because the British head of state , King George V would not be there either .