Tillerson became Secretary of State on February 1, 2017. An unconventional choice for the role, Tillerson's tenure was characterized by a lack of visibility in comparison to his predecessors in the traditionally high-profile position of Secretary of State. During Tillerson's tenure, new applications to work for the Foreign Service fell by 50 per cent, and four of the six career ambassadors as well as 14 of the 33 career ministers, equivalent to military's four- and three-star generals, departed. After their relationship deteriorated, Trump dismissed Tillerson in March 2018, making his tenure one of the shortest in recent history. Tillerson was replaced by Central Intelligence Agency (CIA) director Mike Pompeo.