Developers believe work on the first phase of the former Caltongate site, which will now be known as New Waverley, will be complete by 2016.
The project, which had faced huge opposition from residents in the Old Town World Heritage Site, will link the New Street and East Market Street area and Waverley Station with the Royal Mile.
South African Artisan Real Estate Investors said the five-acre site would be transformed into a pedestrian-friendly urban centre mixing open public spaces with retailers, restaurants, hotels and leisure offerings, as well as new homes and offices.
The first phase, delivering hotels and a new £6.5m public square, is expected to be complete within two years.
Artisan also revealed details of a major new hotel deal, which it claims will breathe new life back into the Old Town.
A 146-suite Adagio Aparthotel will be at the heart of New Waverley, with frontages on to the Royal Mile and the new public square.
The Adagio deal follows another two hotel agreements with Whitbread, announced late last year, for a 127-room Premier Inn and a 130-room Hub by Premier Inn, Whitbread's innovative new "compact" hotel format that will be the first of its kind outside of London.
The scale of the development within the World Heritage Site has been dramatically reduced from the original plans by Mountgrange Capital, which in 2009 fell foul of Unesco inspectors, who called for a total redesign of a large part of the site.
Lukas Nakos, Artisan's managing director, described it as "one of the most challenging development projects anywhere in the UK".
He said: "New Waverley marks the next exciting chapter in the evolution of Edinburgh's Old Town.
"We are well aware of the complexities that surround development in such a sensitive area, which is why we spent almost two years on a comprehensive consultation process bringing together more than 200 local people, businesses, civic partners and heritage bodies."
He said that "following extensive community feedback, our plans for New Waverley now reflect a marked change in direction from previous planning consents, both in terms of improved development quality and in preserving the heritage of such a unique area".
"A closer understanding of our plans shows the massing and overall height of the revised designs has been significantly reduced."
In all, there will be space for some 1750 new jobs, with 720 being created as part of the construction phase of the development.
It is claimed the completed development will generate £43m for the local economy each year.