Matylda, Manon, Lola, and Hodor arrived at the Wiltshire estate in June and have since been seen by visitors enjoying their outdoor pond next to the iconic stately home.
Darren Beasley, head of animal operations at Longleat, said: “We are gradually introducing them to their surroundings and each other as well as spending time with them getting to know their keepers.
“As they came from different places, we are not rushing bringing them together as a four; they have met each other in the House nose-to-nose and are getting used to each other’s scent.
“They are already using their indoor and outdoor pools as well as rotating access in the field.”
The hippos are expected to become a regular sight in the paddock over the coming months.
Visitors can view the new pod from the Jungle Cruise, which is included in the standard day ticket.
Longleat hopes they will be seen in Half Mile Pond regularly from next month.
The hippos’ arrival is part of Longleat’s ongoing efforts to enhance its animal experiences.