LONDON — A former British Army officer has been appointed as the defense secretary in the new Conservative government formed under Prime Minister Boris Johnson.

Ben Wallace, 49, was named as defense secretary after Penny Mordaunt was sacked by Johnson on July 24 after 85 days in office.

The new defense secretary moves over from his post as security and economic crime minister at the Home Office. The post saw him responsible for cybersecurity, counterterrorism and aviation security, among other roles.

Wallace, a Scots Guards officer in the 1990s, earned his mention in official dispatches following a clash with a terrorist unit in Northern Ireland.

Aside from his knowledge of the defense sector gained in military and Home Office appointments, Wallace has experience in the defense industry. He formerly served as the overseas director at British defense technology company Qinetiq before being elected to Parliament.

Mordaunt tweeted her congratulations to Wallace on his appointment, saying that “he knows his stuff and cares deeply about those working in defense and security.” During her short time in office, Mordaunt campaigned for higher defense spending, better pay for soldiers and an expansion of the Royal Navy.

Mordaunt lost her position largely because she backed Foreign Secretary Jeremy Hunt, the loser in the Conservative Party leadership election. She was one of a number of Cabinet ministers who resigned or were sacked by Johnson.

Hunt is rumored to have been offered the defense post but turned it down.

International Trade Secretary Liam Fox was another notable casualty. Fox’s department is responsible for defense exports.

There is no word on other political appointments at the Ministry of Defence, such as procurement minister and armed forces minister.