The Maryland Senate will have a new leader for the first time in 33 years when the legislature reconvenes in January.

As expected, Senate President Thomas V. Mike Miller, the longest continuously serving state Senate president in the country, announced Thursday that he will step down from his leadership role.

Miller, who is 76, attributed his decision to health ailments — prostate cancer that has metastasized to his bone and has caused anemia and fatigue.

“My mind is still strong but my body is weak,” he said at a morning news conference. “And this is a full-time job. It’s a statewide job. And we need somebody younger.”

Miller said he will finish out his four-year term representing his district in Southern Maryland. He was first elected to the House of Delegates in 1970 and to the Senate four years later. He became Senate president in 1987.

To succeed Miller as president, the Democratic Caucus is unanimously supporting Sen. Bill Ferguson, who turned 4 years old the year Miller became Senate president. Ferguson has represented South Baltimore since 2011.

“There is no one that can replace Mike Miller,” Ferguson said, promising to learn from Miller’s experience and guidance.