Developer brothers, Ray and Danny Grehan, have each been ordered to repay debts of more than €300m to the National Asset Management Agency.
The agency took the action against the brothers over multi-million euro borrowings of the brothers' companies, including Glenkerrin Homes, as well as personal borrowings relating to each of the brothers.
Agreement was reached between NAMA and the Grehans and the orders were made by the Commercial Court with the consent of the Grehans.
An order was made against Daniel Grehan for almost €265m and against Ray Grehan for almost €270m.
Orders were also made against the Ashford Partnership, which which owns land in Co Wicklow, for more than €16m and against St Loman's Partnership, which owns land in Lucan in Dublin, for more than €26m.
The summary judgment orders mean NAMA can now take further steps to try to recover the money.
Among the brothers' major assets were The Grange Apartment development in Stillorgan and the UCD Veterinary College site in Ballsbridge in Dublin 4, which Ray Grehan bought for more than €170m in 2005.