The low-lying land of East Central England, known as the Fens, consisted traditionally of semi-continuous marshland and peat bog interspersed with isolated patches of higher ground.

By the 1600s the general drainage situation was so bad that King James I invited Cornelius Vermuyden, the Dutch engineer, to devise a scheme to drain the Great Fen.

It covers some 300,000 acres in the historical counties of Northamptonshire, Norfolk, Suffolk, Lincolnshire, Cambridgeshire and Huntingdonshire and much of it lies below sea level.

The earl and his 12 associates, known as adventurers (i.e. venture capitalists), contracted to drain the southern part of the fens within six years in return for 95,000 acres of the reclaimed land.

[1] The original adventurers were:[2] Work got underway to dig several major new ditches and install sluices at the mouths of river to hold back the high tides.

As time went by and construction costs rose it became clear that the adventurers company organisation was unsuitable for such a longterm project, beset as it was with issues of collecting charges and navigation interests.

The Civil War intervened and the project came to a halt until Vermuyden was able to resume work under parliamentary control in 1649 under the terms and conditions of what came to be called the "Pretended Act".

The corporation's general objectives remained unchanged but its powers in respect of navigation rights and taxation were much improved.

Some of the notable bailiffs were:[3] As the drainage succeeded in its general purpose, albeit with many technical difficulties, the level of the land sank as it dried out, negating the achievement.