In the latest set of results for the Charter Academy in Portsmouth, 72 per cent of students got A* - C grades in English, up from 51 per cent in 2012. Maths was also a particular success with 79 per cent of students getting A*-C in mathematics, up from 70 per cent in 2012.
Charter Academy, which is part of the ARK Schools network, is celebrating an excellent year of GCSE results.
The most recent league tables rank it as the best state school in Portsmouth as well as the most improved. It is also the second most improved school in the whole country for GCSE results.
The school has seen a 47 percentage point rise in students getting five good GCSEs, including English and maths, since becoming an ARK school in 2009, making it now the best school in the city.
Charter Academy is also the best school in Portsmouth based on the amount of progress that pupils make.