Morris was British & was active between 1663 & 1672 within the Caribbean.
He was one of the captains taking part in the raids upon Mexico & Nicaragua in late 1663 or early 1664. The others participating in these raids were Henry Morgan, David Marteen, Captain Jackman & Captain Freeman. At the time of the raids, raids on Spanish possessions had been prohibited, but the captains pretended to be acting under a privateering commission issued by the Jamaican governor, Thomas Modyford.
In Mexico, they had anchored their ships at the mouth of the Grijalva River & marched 50 miles inland to Villahermosa, the capital of the Tabasco Province. They took the garrison by complete surprise. Returning to the coast, they found that their ships had been taken over by Spaniards. They stole 6 small boats & paddled south, stopping to sack a small town along the way. They then went to Trujillo, Honduras where they seized a ship at anchor. Then procceded to the mouth of the San Juan river where they hid their ships & using the small boats they had captured, rowed 100 miles up-river to Granada on Lake Nicaragua.
According to Jamaican Governor Thomas Modyford ''marched undiscried into the center of the city, fired a volley, overturned 18 great guns in the Parada Place, took the serjeant-major's house, wherein were all their arms and ammunition, secured in the Great Church 300 of the best men prisoners, abundance of which were churchmen, plundered for 16 hours, discharged their prisoners, sunk all the boats, and so came away.''
After the sack of Granada, the pirates went back to Port Royal, Jamaica, arriving there in November 1665. This was an unparalled voyage, consisting of several thousand miles, reaching far inland, & the seige of three towns of high importance.
Morris would further be part of Morgan's raids on Portobelo in 1668, Maracaibo in 1669 & Panama in 1671. Morris along with Lawrence Prince led the Panama assault. The assault on Panama came after a peace treaty had been signed between England & Spain. As the governor of Jamaica had commissioned the raid, he was arrested & Thomas Lynch became the new governor. Lynch then arrested Morgan. Lynch gave Morris a frigate & ordered him to seek out & arrest any captains refusing to quit their piratical activities.