The County Council realised that this venture could only be achieved by working in partnership with the private sector and by securing grant funding.

Following a selection process, the Trevor Osborne Group was chosen as its development partner the first of a number of successful partnerships across the site.

With its long history and connection to the Castle, Oxford Preservation Trust understood the importance of the site and the positive contribution that they could make by becoming more closely involved taking responsibility for the ancient buildings which were less likely to have commercially viable alternative uses. These included the Mound, St George's Tower, and D Wing, now the heritage attraction and education centre, and so the Trust became the third partner in the development.

This provided the opportunity to bring together many of the Trust's primary objectives, protecting the site for its character, history and setting within the city, an enabling the Trust to provide better education and understanding of the city's heritage, whilst ensuring that the overall redevelopment of the site respected and responded to its historic, architectural and archaeological significance. On completion of the development, OPT took a fifty year lease of a significant part of the site including the buildings and structures around the Castleyard, which it redeveloped and subsequently sub-let to experienced commercial operators, Continuum, who run Oxford Castle & Prison and the Key Learning Centre.

Grant funding was secured from SEEDA (South East England Development Agency), Historic England, the Heritage Lottery Fund and the Trust For Oxfordshire's Environment.

With shared vision, open lines of communications and a team approach, the partnership worked together to drive the project forward. Over the months of construction, there was a range of obstacles that needed to be overcome including delays from public utilities, arson and a main contractor going into liquidation. All of these difficulties and others were managed and absorbed proving the true strength of the partnership.

Oxford Castle Ltd. was required to carry out the restoration work to the historic buildings and provide enabling works for the Oxford Preservation Trust development before the lease from the County Council was granted or any of the commercial businesses could open. The value of these enabling works were treated as match funding and helped the Trust to secure just over £4m from the Heritage Lottery Fund.