The party and its paramilitary wings played a major role in the Lebanese Civil War (1975–1990), opposing Palestinian insurgency in South Lebanon as well as collaborating with Israel.

Kataeb is the plural of Katiba which is a translation into Arabic of the Greek word phalanx ("battalion") which is also the origin of the Spanish term Falange.

[19]Pierre founded the party along with four other young Lebanese: Charles Helou, who later became a President of Lebanon, Chafic Nassif, Emile Yared, and Georges Naccache.

This approach starkly contrasted with the ideology of the Syrian Social Nationalist Party (SSNP), which emphasized the primacy of the nation over the intrinsic value of the individual.

The adoption of these ideas marked a significant shift within the party and was particularly popularized by young Phalangist intellectuals who had encountered Mounier's thought during their university studies in France.

By the end of the decade, the party created its own militia, the Kataeb Regulatory Forces (KRF) and soon clashes began with the rising Palestinian militant guerrillas.

It was founded in 1937 as the "Militants' organization" by the President of the Party Pierre Gemayel and William Hawi, a Lebanese-American glass industrialist, who led them during the 1958 civil war.

In order to coordinate the activities of all Phalange paramilitary forces, the Political Bureau set up the Kataeb War Council (Arabic: Majliss al-Harbi) in 1970, with William Hawi being appointed as head.

[25] The seat of the Council was allocated at the Kataeb Party's Headquarters at the heart of Ashrafieh quarter in East Beirut and a quiet expansion of KRF units followed suit, complemented by the development of a training infrastructure.

[25][26] Considered by many analysts as the best organized of all militia "fiefs" in the whole of Lebanon under the leadership of "chef" Boutros Khawand, it was administered by a network of Phalangist-controlled business corporations headed by the GAMMA Group "brain-trust", backed by the DELTA computer company, and the SONAPORT holding.

The latter had run since 1975 the legal commercial ports of Jounieh and Beirut, including the infamous clandestine "Dock Five" – "Cinquième basin" in French – from which the Phalange extracted additional revenues by levying illegal taxes and carried out arms-smuggling operations.

[27][28][29] The KRF was served by a clandestine-built airstrip, the Pierre Gemayel International Airport, opened in 1976 at Hamat, north of Batroun,[30] and had its own radio station "The Voice of Lebanon" (Arabic: Iza'at Sawt Loubnan) or "La Voix du Liban" (VDL) in French set up in 1976.

In July–August of that same year, the Phalangists headed alongside its allies, the Army of Free Lebanon, Al-Tanzim, NLP Tigers Militia, Guardians of the Cedars (GoC), the Tyous Team of Commandos (TTC) and the Lebanese Youth Movement (LYM) in the sieges – and subsequent massacres – of Karantina, al-Masklah and Tel al-Zaatar Massacres[31] at the Muslim-populated slum districts and adjacent Palestinian refugee camps of East Beirut, and at the town of Dbayeh in the Metn.

[citation needed] In 1958 the Kataeb was the key actor in confronting the coup influenced by pan-Arabists led by Gamal Abdel Nasser, President of the ephemeral United Arab Republic (Egypt, Syria, and Yemen), and succeeded in maintaining Lebanon's independence and liberal identity.

[20][failed verification] After having succeeded in preserving the Lebanese formula, Kataeb Party ranks grew considerably and reached 70,000 members, out of a total population of 2.2 million.

The party played a key role in promoting modern institutions that are still today the pillars of the Lebanese administrative system, including the Civil Service Council, the Central Inspection Board, and many others.

[20][failed verification] Pierre Gemayel, leader of the party and minister of public works, gave Lebanon a large part of its modern infrastructure by completing 440 development projects during his term.

Many foreign states were directly and militarily involved in the Lebanese conflict, especially Syria, which, under the banner of Arab solidarity, tried to impose its authority upon the country, and Israel, which invaded Lebanon in 1978.

Despite the turmoil caused by the civil strife in Lebanon and the raging wars that devastated the country, President Gemayel was able to accomplish many achievements during his presidential mandate.

[citation needed] One of his first achievements was to rebuild the State's institutions and to reorganize and resupply the Army in preparation for the struggle to recover sovereignty and provide security for Lebanon.

[citation needed] He rebuilt the Lebanese University and laid its modern foundation, introduced many economic reforms, and started to rebuild Beirut's central district.

Eventually, all this led to the Independence Uprising in February 2005 and on 14 March 2005 more than a million Lebanese filled the streets of central Beirut to demand Syrian withdrawal and the restoration of sovereignty.

The Kataeb Party extensively participated in the Cedar Revolution and MP Pierre Gemayel played a significant role in shaping this uprising which led to Lebanon's second independence.

[50] Samy Gemayel emphasized: We, as the Kataeb party, have alone faced surrender to Hezbollah's will, isolating Lebanon from its surroundings, electing Michel Aoun as president, the electoral law that gave the majority to Hezbollah, and quotas and fictitious budgets such as taxes, power ships, and seaports.On 2 April Nadim Gemayel, a cousin of Samy, promoted his candidacy in a speech during a small event.

This reconciliation was marketed as a gesture of goodwill from Pierre Amine Gemayel who deemed it was time to turn the page and give those who were unfaithful to the party principles a second chance.

Practically, it was a way for Pakradouni and his men to leave the Party with as little humiliation as possible since the reconciliation deal stipulated the resignation of the entire political bureau after 2 years.

Samy Gemayel, Amine's second son, had formed his own political ideas and identity at the time, much closer in principle and in a manner to those of his uncle Bachir.

[citation needed] The Party has an active parliamentary group and has MPs elected in nearly all major Christian constituencies such as Beirut, Metn, Zahlé, Aley, and the North.

On 11 March 2018, the Kataeb Party unveiled its 131-point platform, in which they expressed some progressive values such as decriminalizing homosexuality, abolishing capital punishment, removing censorship laws, and adopting a 30% female quota system in the parliament.

[50] Samy Gemayel emphasized:We, as the Kataeb party, have alone faced surrendering to Hezbollah's will, isolating Lebanon from its surroundings, electing Michel Aoun as president, the electoral law that gave the majority to Hezbollah, and quotas and fictitious budgets such as taxes, power ships, and seaports.On 2 April Nadim Gemayel, cousin of Samy, promoted his candidacy in a speech during a small event.