What is a English word for the events that are part of a larger event?

For example in the event "solar eclipse", there are different phases or stages (https://www.timeanddate.com/eclipse/total-solar-eclipse.html):

1. Partial eclipse begins
2. Total eclipse begins ...

A solar eclipse is quite predictable and "linear": after phase 1, there will be phase 2 and so on. But what when the larger event is "non linear"? With my German background, where the translation of phase has a clear linear meaning (https://www.duden.de/rechtschreibung/Phase), phase seems wrong to me. I would rather use something like sub event.

Or is my understanding of phase wrong, and it is not as linear as in the German Phase, or the English stage (https://www.lexico.com/en/definition/phase)?

Example sentence:

The negotiations between the UK and EU, Theresa May's resignation and the related protests are _______ of the Brexit.

What is an English word for the events that are part of a larger event?

For example in the event "solar eclipse", there are different phases or stages (https://www.timeanddate.com/eclipse/total-solar-eclipse.html):

1. Partial eclipse begins
2. Total eclipse begins ...

A solar eclipse is quite predictable and "linear": after phase 1, there will be phase 2 and so on. But what when the larger event is "non linear"? With my German background, where the translation of phase has a clear linear meaning (https://www.duden.de/rechtschreibung/Phase), phase seems wrong to me. I would rather use something like sub event.

Or is my understanding of phase wrong, and it is not as linear as in the German Phase, or the English stage (https://www.lexico.com/en/definition/phase)?

Example sentence:

The negotiations between the UK and EU, Theresa May's resignation and the related protests are _______ of the Brexit.

What is a English word for the events that are part of a larger event? For example in the event "solar eclipse", there are different phases or stages (https://www.timeanddate.com/eclipse/total-solar-eclipse.html): 1. Partial eclipse begins, 2. Total eclipse begins ... A solar eclipse is quite predictable and "linear": after phase 1, there will be phase 2 and so on. But what when the larger event is "non linear". With my German background, where the translation of phase has a clear linear meaning (https://www.duden.de/rechtschreibung/Phase), phase seems wrong to me. I would rather use something like sub event.

Or is my understanding of phase wrong, and it is not as linear as in the German Phase, or the English stage (https://www.lexico.com/en/definition/phase)?

Example sentence:

The negotiations between the UK and EU, Theresa May's resignation and the related protests are _______ of the Brexit.

What is a English word for the events that are part of a larger event? 

For example in the event "solar eclipse", there are different phases or stages (https://www.timeanddate.com/eclipse/total-solar-eclipse.html):

1. Partial eclipse begins
2. Total eclipse begins ...

A solar eclipse is quite predictable and "linear": after phase 1, there will be phase 2 and so on. But what when the larger event is "non linear"? With my German background, where the translation of phase has a clear linear meaning (https://www.duden.de/rechtschreibung/Phase), phase seems wrong to me. I would rather use something like sub event.

Or is my understanding of phase wrong, and it is not as linear as in the German Phase, or the English stage (https://www.lexico.com/en/definition/phase)?

Example sentence:

The negotiations between the UK and EU, Theresa May's resignation and the related protests are _______ of the Brexit.