Robert is a prominient character of House of Anubis and is mentioned many times in the series. His evil side is also a main antagonist in Season 3.
Robert got married twice. He was married with KT's Great Grandmother and they had KT's Granpa. However, it is unknown what happened to his first wife. He then got married again with Louisa Frobisher-Smythe and they had Sarah Frobisher-Smythe. Robert was also cursed by Anubis for taking the blame of robbing a cursed tomb. This was all revealed in Season 3.
He also made the tunnels and his wife made the replica of the Mask of Anubis. They also scattered the pieces of the Cup of Ankh and didn't tell anyone where they were hidden.
In Season 1, Robert is mentioned to be the founder of Anubis House along with his wife. He is revealed to have been the one to have scattered the pieces of the Cup of Ankh. His soul is seen with Sarah and Louisa and is resting in peace
In Season 2, Robert is heavily mentioned. He made the tunnels seen and is the one who installed the many booby traps and is mentioned a lot of times.
In Season 3, Robert is seen in a tank. He is reawakned by Victor Rodenmaar Jr., Caroline Denby, and Eric Sweet along with the descendants. He is reawakened evil and attempts to bring Ammut into the world. However, he must capture five sinners. He is able to capture Victor but makes Evil Victor and Caroline to capture more sinners. They are able to capture Patricia, who captures no one. However, Caroline and Evil Victor are able to capture Eric for him. He himself then capture Fabian. The final sinner is captured by Robert himself and Caroline.
Robert is able to bring back Ammut when KT and Eddie bring the Staff of Osiris to the Tank Room. He is given a book by Ammut which turns anyone into a sinner as long as they don't have KTs key as protection. Robert's evil side is destroyed when Ammut is defeated. He then ages and becomes good again. He then goes to Egypt with Harriet Denby.