Arsenal owner Stan Kroenke and director Josh Kroenke have been appointed co-chairs in a boardroom restructure.
Tim Lewis also becomes executive vice-chair having been on the board as a non-executive director since 2020.
Stan Kroenke, 75, acquired a 9.9% stake in Arsenal in 2007, becoming majority shareholder in 2011 and assuming 100% ownership in 2018.
The American said the changes "further reaffirms our family's long-standing commitment to this great club".
Josh Kroenke is Stan's 42-year-old son and was appointed a non-executive director in 2013.
In a statement Stan Kroenke added: "Stability in football has never been more important as we move past the [Covid] pandemic, and we believe this is the perfect time to formalise these roles.
"Our objectives and ambition will never waver - to field teams that compete for trophies at the highest level and lead our club in a way that inspires our passionate supporters around the world."
Arsenal are currently five points clear at the top of the Premier League with 11 games remaining as they seek a first title since 2004.
