A war protester convicted of climbing over a security fence at a military air base in Northants has begun an appeal.
Mrs Percy is married with three children and four grandchildren
Lindis Percy, 62, of Hull, hung an American flag bearing the words "war in Iraq - immoral, illegal, madness" on a gate at RAF Croughton.
In March 2003, the grandmother of four was fined £200 for aggravated trespass.
Percy, a veteran protester, is claiming she could not be guilty as the offence involves disrupting lawful activity and she says the Iraq war was "illegal".
She has been a campaigner for 20 years and is joint co-ordinator of the Campaign for the Accountability of American Bases.
The group says that as US bases were involved in the Iraq war, they were not operating lawfully under international law.
The hearing is expected to last until Wednesday.