In 1276 the burgesses of Derby lodged a complaint against St Mary’s Abbey and the Bishop of Chester [sic – it should have been Lichfield] that they had obstructed the course of the River Derwent by dams. In 1283, the abbot led nearly 100 armed men including Richard de Normanton and John de Lincoln against the brethren of Burton Lazars who had occupied one of the mills. The abbot's men threw the others out, doing £100's damage. The Master of Burton Lazars complained to the crown, and Nicholas de Stapleton and William de Meynill were told to settle the matter using a local jury. The outcome is not known.

A few years’ relative peace ensued: in 1278 Abbot Lawrence supervised an election at Beauchief Abbey in South Yorkshire, and he is named in another deed in the Chartulary. In 1281 the king challenged the Abbey’s right to some lands in Sandiacre, an ongoing battle from Abbot John’s time, and there was a dispute about the enclosure of land in Stanton-by-Dale. In 1283 Pope Martin IV confirmed St Mary’s Abbey's liberties.

Peace was not to last. In the early 80s, there arose a dispute with the prior of Dunstable and others about the enclosure of pasture land at Bradbourne in the Peak. The abbots of St James without Northampton and the priors of St Albans and St Andrews, Northampton, received a papal mandate in 1283 to settle the matter, which they did at Bedford on 3rd May 1286.

Then in 1287 there was further dispute about the enclosure of land in Sandiacre; Abbot Lawrence also contested an eviction order from lands in Sandiacre and Ockbrook. He fought Ralph de Cromwell, Lord of West Hallam, who enclosed about half the common pasture of West Hallam; he won and recovered the abbey’s common land, but Cromwell later broke down the abbey's weir at North Muskham, for which the abbey was awarded 6/8d. damages.

1287 also marks the last mention of lay brothers at St Mary’s Abbey. It is no longer possible to ascertain where they might have been accommodated.

Soon after Abbot Lawrence’s retirement he received a letter from Robert de Derby, a canon, begging him to reconcile the apostate but repentant lay-brother, Edmund Pouche or Zouche.

Abbot number seven:  Richard de Normanton
Abbot Richard ruled for eight years minus ten days from September 1289 to September 1297. He was said to be a squanderer. Something of his earlier life and career is known: in 1282 he had participated, contrary to the statutes of the order, in the baptism at Stapleford, of Richard, son and heir of Hugh le Heryz; and in 1283 he was involved in the fight over Ockbrook Mill (see Abbot Lawrence). In 1290 Abbot Richard also received an appeal from