In 989 Bruno, Bishop of Langres, requested Mayeul, Abbot of Cluny, to send monks to re-settle the abbey, grown decadent, as a Cluniac house.

By 1002, the ruin of the previous building had been razed and construction began on a new Romanesque structure designed by William, consisting of a subterranean church round the sarcophagus of Benignus, a ground floor church for worship, and a rotunda,[3] 17 metres in diameter, on three levels in the place of the apse, linking the two.

[a] Dedicated in October 1016 by Lambert I,[4] this suite of buildings was decorated in the ornate Cluniac style, of which only a few traces survive.

In 1272 the crossing tower collapsed, destroying the whole of the upper church and severely damaging the subterranean one, and smashing some of the supporting columns of the rotunda.

Then the abbot, Hugh of Arc, of a powerful Burgundian family, was able, thanks to his contacts, to mobilise enough support to begin the construction of a new Gothic abbey church in 1281.