You will be given a definition of a task first, then some input of the task.
This task is about creating an unanswerable question based on a given passage. Construct a question that looks relevant to the given context but is unanswerable. Following are a few suggestions about how to create unanswerable questions:
(i) create questions which require satisfying a constraint that is not mentioned in the passage
(ii) create questions which require information beyond what is provided in the passage in order to answer
(iii) replace an existing entity, number, date mentioned in the passage with other entity, number, date and use it in the question
(iv) create a question which is answerable from the passage and then replace one or two words by their antonyms or insert/remove negation words to make it unanswerable.

Passage: The Arians no longer presented an unbroken front to their orthodox opponents. The Emperor Constantius, who had been the cause of so much trouble, died 4 November, 361 and was succeeded by Julian. The proclamation of the new prince's accession was the signal for a pagan outbreak against the still dominant Arian faction in Alexandria. George, the usurping Bishop, was flung into prison and murdered. An obscure presbyter of the name of Pistus was immediately chosen by the Arians to succeed him, when fresh news arrived that filled the orthodox party with hope. An edict had been put forth by Julian permitting the exiled bishops of the "Galileans" to return to their "towns and provinces". Athanasius received a summons from his own flock, and he accordingly re-entered his episcopal capitol on 22 February, 362.
Output:
Who preceded Emperor Constantius?