The viscounty became extinct upon his death .
Lord Slane ( who had succeeded to the title Baron Slane in 1676 ) was created The 1st Viscount Longford by Queen Anne in 1713 .
The viscounty became extinct upon Slane 's death .
Lord Slane ( who had succeeded to the title Baron Slane in 1676 ) was created The 1st Viscount Longford by Queen Anne in 1713 .