What is the ruling on one who broke a series of oaths in which he swore to do something, then swore not to break his first oath, then broke them all?

Your repeated oaths regarding a single matter are considered one oath. Similarly, your repeated swearing not to break this oath is also considered one oath. Therefore, you are liable for two expiations: one for the oath concerning the matter you broke, and another for the repeated oaths not to break it.

Scholars differed regarding the multiplicity of expiation when oaths are repeated and then broken: 1. The majority: One expiation for repeated oaths concerning a single matter. They cited the hadith of Ibn Umar, "If you swear many times, then there is one expiation." This applies if one has not broken the oath. However, if one breaks an oath, then swears again, and breaks it again, an expiation is required for each breach, unlike the Hanbalis who also obligate a single expiation in this case. 2. The Hanafis: An expiation is due for each oath. 3. Some Malikis and Shafi'is: If the swearer intended affirmation, then there is one expiation; if he intended renewal, then there is an expiation for each oath.

The first opinion is the most preponderant due to the existence of evidence.