Foreign income before I moved to the UK

Hello!

Some information about myself:
- I am a US citizen that moved from the USA to the UK in late 2019.
- I started working for the UK subsidiary of US multinational after I moved to the UK.
- Before my move, I have always lived and worked in the USA.

My question has to do with the UK 2019-2020 tax year (I guess April 2019 to April 2020?).

Will the HMRC want to know about any of my income earned *before* I moved to the UK? Or are they only concerned about all sources of income *starting* from the day I moved to the UK?

Thanks in advance!

In a similar situation I moved from the USA to UK in May 2016 and my UK tax return was considered a split year  with no income counted prior to my arrival in May.

Wonderfully clear answer - thank you!