Recent research[1] has uncovered a charter, dated 3 November 1421, was issued at Cumbernauld Castle and was used to formally grant James Fleming his father's land, following allegations of murder.

The country was much too impoverished to permit anything more ambitious, such as the great courtyard strongholds built before the death of Alexander III.

As time went on, and the power and influence of the family grew, the castle would have been enlarged by the addition of other stone structures, such as a great hall for festive occasions.

In March 1544, an unexpected English visitor during the War of the Rough Wooing, Edmund Storey, a servant of Thomas Wharton, described his reception by Lord Fleming;"On the morrow, in riding towards Stirling, we came to Lord Fleming's castle of Cumbernall, and alighted near the castle gates, at which the Scotsman knocked and told the porter that a servant of the Master of Maxwell's came with a message.

Part of the courtyard buildings are still standing, particularly the wall that separates the lower service area from the car park.

On the lower side of this, there is a long row of corbels or projecting stones, of a distinctive 16th century pattern, designed to support timbers of a lean-to building.

The murders made James IV a frequent visitor to Cumbernauld, Margaret Tudor accompanying him on one occasion.

Regent Lennox sacked Cumbernauld in September 1570 and expelled his wife Elizabeth Ross and her three infant children.

[11] Herman Moll's 1745 map has a brief mention of Cumbernard Castle even though it had been replaced by the House in 1731 unless the reference is to the stable destroyed in 1746.

It says: Vestigia valli Romanorum quod videtur Agricolam aut Adrianum Primum posuisse Which translates as: 'the remains of the Roman fortification which it seems Agricola or Hadrian first built'

"[15] Hector Boece mentioned the Caledonian white cattle at Cumbernauld in his Historia Gentis Scotorum, (1527), which were also kept in the Torwood Forest near Stirling.

In 1963-64, Cumbernauld Historical society, in co-operation with Glasgow archaeological society excavated an area to the north-east of Cumbernauld House and uncovered part of the domestic periphery of the castle, comprising a 15th-century rubbish chute, an adjoining prison and cellar and a well house reached by a flight of steps.