Finding that Somerset, though degraded from his dignity, and even lessened in the public opinion by his spiritless conduct, still enjoyed a considerable share of popularity, he determined to ruin the man whom he regarded as the chief obstacle to the attainment of his hopes.

The alliance which had been contracted between the families had produced no cordial union, and only enabled Northumberland to compass with more certainty the destruction of his rival.

He secretly gained many of the friends and servants of that unhappy nobleman: he sometimes terrified him by the appearance of danger; sometimes provoked him by ill usage.

The unguarded Somerset often broke out into menacing expressions against Northumberland: at other times he formed rash projects, which he immediately abandoned his treacherous confidants carried to his enemy every passionate word which dropped from him: they revealed the schemes which they themselves had first suggested: and Northumberland, thinking that the proper season was now come, began to act in an open manner against him.
In one night, the duke of Somerset, Lord Grey, David and John Seymour, Hammond, and Neudigate, two of the duke's servants, Sir Ralph Vane, and Sir Thomas Palmer, were arrested and committed to custody.

Next day, the duchess of Somerset, with her favorites Crane and his wife, Sir Miles Partridge, Sir Michael Stanhope, Bannister, and others, was thrown into prison.