Maryland Code, Real Property § 6-103

No person may commence an action for the recovery of land, nor make an entry on it, by reason of a breach of a condition subsequent, or by reason of the termination of an estate of fee-simple determinable, unless the action is commenced or entry is made within seven years after breach of the condition or from the time when the fee-simple determinable estate terminates. If a breach of a condition subsequent or termination of a fee-simple determinable estate occurred prior to July 1, 1969, an action may be commenced for the recovery of the land, or an entry may be made on it, by the owner of a right of entry or possibility of reverter by July 1, 1976. Possession of land after breach of a condition subsequent or after termination of an estate of fee-simple determinable is adverse and hostile from the first breach of a condition subsequent or from the occurrence of the event terminating the fee-simple determinable estate.