Towneley returned to Britain sometime before 1743 and lived quietly in
Wales. His French officer's commission was renewed in late 1744, which suggests he had been identified for a senior role in any invasion. Hearing of Charles' landing in north-west Scotland in August 1745, he traveled to
Manchester, with two prominent Welsh Jacobites,
David Morgan and William Vaughan. They met other Jacobite sympathisers at
Didsbury, among them the poet
John Byrom, who described Towneley as a "gallant soldier", devoted to the Stuart cause, but was shocked by his "profane swearing". When the Jacobite army arrived on 28 November, Towneley and others formed the
Manchester Regiment, the only significant English unit raised in 1745. Vaughan and many recruits were Catholic, including a group of 39 from
Kirkham, Lancashire, but the gentry generally avoided involvement. Since 1721,
Walpole's government pursued a policy of reconciling Catholics to the regime, while closely monitoring any of doubtful loyalty, and the Jacobites made little effort to raise them. Since most felt a Stuart monarch would do little to improve their status, joining the rebellion offered little gain for an enormous risk. ,
Kilmarnock and
Balmerino (immediately behind Lovat) and Towneley and Fletcher, their heads on spikes at the rear. Towneley was appointed colonel on the recommendation of unofficial French envoy, the
Marquis d’Éguilles, who knew his brother John. Although viewed favourably by Irish Jacobite Sir John MacDonald, this opinion was not universally shared; Towneley had a reputation for being hot-tempered and one of his officers,
James Bradshaw, transferred to
Lord Elcho's regiment as a result. The unit was issued with weapons and ammunition at
Macclesfield on 1 December but attempts to attract additional recruits were unsuccessful. The Scots had agreed to the invasion only when Charles promised they would receive widespread English support; there was no sign of this and at
Derby on 5 December, they insisted on retreat. Morale among the English collapsed and while a few enlisted on the return from Derby, there were an increasing number of desertions. By 19 December, the Jacobites had retreated as far as
Carlisle, captured in
November, which Charles wanted to retain, as a statement of his intention to return. With his remaining 115 men, Towneley volunteered to join the garrison of 200 under John Hamilton of Sandistoun, an officer from the Duke of Perth's Regiment. According to Adjutant-general
O'Sullivan, his officers believed it was easily defensible and they could hold out for good terms. Given
Cumberland wanted to execute those responsible for surrendering the castle in November, this was probably an accurate assessment. However, when government forces reached Carlisle on 22 December, morale and supplies were low and most of the Jacobite officers considered defence futile. At Towneley's trial, a witness claimed he told Hamilton it was "better to die by the sword than fall into the hands of those damned Hanoverians". He was overruled by the others present and
the castle surrendered on 30 December. Two officers from Lallys escaped over the wall and made their way to Scotland; the other French-Irish regulars were treated as
prisoners of war and later exchanged. The Manchesters were only granted their lives, subject to the "King's pleasure"; this meant they would receive a trial, rather than being summarily executed. ==Trial and execution==