On 4 September 1397 , he was ordered to arrest his uncle , Sir Thomas Mortimer for treason regarding his actions at the Battle of Radcot Bridge .
On 4 September 1397 , he was made no real attempt to do so .
On 4 September 1397 , he was ordered to arrest his uncle , Sir Thomas Mortimer for treason regarding his actions at the Battle of Radcot Bridge , but made no real attempt to do so .