A messaging system and method which allows parallel execution of related requests according their context-based sequence. A serialization processor receives each incoming message request from a messaging client, extracts a transaction identifier (TI), searches a state table for the TI, and, if the TI is found active in the state table, stores the request in a serialization queue and makes an entry for that TI with the state “queued” in the state table. After execution of the active request, its entry in the state table is cleared, and the queued request with the same TI is executed, whereupon its entry is changed from queued to active.