The charge was sedition, for speaking against the established order. Northampton and two confederates, John More and Richard Norbury, were tried and found guilty. One of Northampton's servants during his term as mayor, Thomas Usk, turned informant on Northampton.
Northampton appealed to John of Gaunt, but received no support. A death sentence for the three men was commuted to 10 years in prison. To prevent any kind of collusion between them, they were sent to separate facilities, all at least 100 leagues (1 league = 3 miles) outside of London. Northampton wound up at Tintagel.
Northampton only served a couple years: he was pardoned by Richard II (Richard had supported Northampton when running for his first term as mayor, but did not support him against Brembre), but not allowed to return to London.
Then came the Merciless Parliament in 1388, which (among other things) led to the execution of Brembre and Thomas Usk. In 1395 Northampton's London citizenship was restored. The end of his life was comfortable: at his death he left property worth £5000. He was a benefactor of the Charterhouse monastery, a Carthusian establishment. He died in 1398 and was buried in the church of the Hospital of St Mary de Elsyngspital in London.
Who was Thomas Usk, the man who informed on Northampton? He was a minor civil servant, but also a poet, writing a work that was once assumed to have been by Chaucer. I'll tell you more about this minor poet tomorrow.
