This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.

However Cornelius Clifford places his birth no earlier than 296 and no later than 298, based on the fact that Athanasius indicates no first hand recollection of the Maximian persecution of 303, which he suggests Athanasius would have remembered if he had been ten years old at the time. Secondly, the Festal Epistles state that the Arians had accused Athanasius, among other charges, of not having yet attained the canonical age (30) and thus could not have been properly ordained as Patriarch of Alexandria in 328. The accusation must have seemed plausible. The Orthodox Church places his year of birth around 297.
What famous event happened in 303?