The next leap year after year 239 is year 240. Explanation:

• According to the Julian calendar, a leap year occurs every 4 years.
• Since 239 is not divisible by 4, the next year that is divisible by 4 after 239 is 240.
• Therefore, year 240 is the next leap year after 239.

This follows the basic rule used by the Julian calendar for leap years, which was historically in use during that far past time period.