President Trump said on Monday he has removed Federal Reserve governor Lisa Cook from her post, following through on a threat to oust her if she refused to resign.

President Donald Trump on Monday said he has fired Federal Reserve Governor Lisa Cook, according to a letter addressed to her posted on his social media — the first instance of a president firing a central bank governor in the central bank’s 111-year history.

Shares in stock markets around the globe were sinking after President Donald Trump said he’s firing Federal Reserve Governor Lisa Cook, an unprecedented move and sharp escalation in his battle to control the central bank,