 One Cony, a city merchant, had been arrested by order of the council of state for non-payment of taxes, and Maynard, with Serjeants Thomas Twysden and Wadham Wyndham, moved on his behalf in the upper bench for a habeas corpus.Their argument on the return, 18 May 1655, amounted in effect to a direct attack on the government as a usurpation, and all three were forthwith, by order of Cromwell, committed to the Tower of London; they were released on making submission (25 May).Maynard was among the commissioners appointed to collect the quota of the Spanish war tax of 1657 payable by Devon.