The Orange Order has said it hopes two new museums will promote understanding and increased tolerance of it.
The institution has been awarded almost £4m for interpretative centres in Belfast and Armagh.
Funding from the European Union's Peace III programme will be used to revamp the Orange Order headquarters at Schomberg House and Sloan's House.
Orange Lodge of Ireland grand master Edward Stevenson said: “The aim of this transformational project is to create understanding, education, tolerance and mutual respect through interpretation and creation of shared space.
“The creation of two unique educational and resource centres will tell the story of the foundation of the institution as well as its traditions, development and place in wider society.
“Such world-class developments at both Schomberg House and Sloan's House will also preserve and present the impressive historical collections of the Orange Order in a form that will encourage an informative and engaging learning process.”
The extension of Schomberg House in east Belfast will include a replica Orange hall.
A range of items including a letter written by William III before his departure to Ireland in June 1690, a book of payments to the Williamite army in 1690, and a lock of his hair will be put on display.
The new building will also incorporate a research facility and educational resource, with particular access for school and cross-community focused visits.
Refurbishment of Sloan's House in Loughgall, Co Armagh — where the first Orange warrants were signed more than 200 years ago— will include a museum exhibition area to provide information on the history of the Orange Order.
A musket with bayonet used during the 1795 Battle of the Diamond at Loughgall will be among the artefacts on show.
Five full-time staff will be appointed to run both sites, expected to be open by summer 2014.
The Reach project (Reaching out through Education and Cultural Heritage) received a total of £3.6m from the EU's Peace III programme, managed by the Special EU Programmes Body.
Pat Colgan, chief executive of the Special EU Programmes Body, said: “Upon its completion, this EU-funded project will promote a greater awareness of the history and traditions of the Order.”
Match-funding for the project has been provided by the Department for Social Development and the DoE in the Republic.
DSD Minister Nelson McCausland said the new centres would help cement the Orange Order in society.
The Republic's Environment Minister, Phil Hogan TD, said the new project could create greater levels of mutual understanding on both sides of the border, adding: “I am also pleased to see that it will involve a comprehensive cross-border element.”