"If you want to listen diligently and carefully consider, how much We have always put [our trust] in you, and how We supported you, to Our great shame, also by breaking the truth, you will understand, not because of Our harshness, but because of the quality of your merits that We are denying the solemn consolation of the Apostolic Blessing from you.
Because you can remember enough how much you were impenitent and rebellious towards us [...] how much shame and injustice, how much contempt and insult We were forced to endure from you in the matter of the said Archbishop [Andrew], who [...] was excommunicated and declared oath-breaker by you despite Our ban. [...]
You defame at the speck in your brother's eye, but do not consider the planks of arrogance and self-praise in your own eye [Mt. 7,3], you became one of those – as is clear from your frequent actions – of said: Blind guides, who strain out a gnat and swallow a camel [Mt. 23,24]. [...]
As We once commanded you and leave it in the virtue of obedience, do not avoid the aforementioned Archbishop anymore, do not preach to others should avoid, furthermore do not dare to claim that the he is a member of the Devil, excommunicated or oath-breaker.
Be aware of it, if you continue to dare to avoid this Archbishop, We will avoid you, an excommunicated, and We also ordered everyone else to avoid you [...]."

— Pope Alexander III's letter to Archbishop Lucas in March 1179
Following the death of Stephen III, a Hungarian delegation visited Emperor Manuel and Béla in Sardica (now Sophia in Bulgaria) and invited the prince to the Hungarian throne.
Béla, who lived in Constantinople since 1163 and was the former designated heir of the Byzantine Empire, arrived in Hungary with his wife Agnes of Antioch in Székesfehérvár in late April or early May. It is uncertain if Archbishop Lucas initially supported Béla's claim (as historian György Györffy and András Kubinyi argued), or if he was against Béla's invitation from the beginning.
In a letter written by Pope Alexander III, Béla was unanimously elected king by the "dignitaries of the Hungarian kingdom", including Lucas.
However, Béla's coronation was delayed because Lucas refused to perform the ceremony.
The Archbishop accused the king of simony because Béla had given a precious cloak (pallium) to his delegate.
A theory suggests that Lucas also feared that the influence of "schismatics" would increase under Béla's rule.
Nevertheless, the majority of the barons and prelates remained loyal to Béla, who sought the assistance of the Holy See against the archbishop.
Pope Alexander III imposed a papal rebuke on Lucas for his inflexibility and ordered him to crown Béla, but the archbishop continued to refuse to crown Béla III.
Upon Béla's request, Pope Alexander III temporarily authorized the Archbishop of Kalocsa (presumably Chama) to anoint Béla king and perform his coronation, which took place on 18 January 1173.

Lucas became a member of the internal opposition which rejected Béla's reign.
The archbishop allied with his former opponent Queen Euphrosyne and supported the aspirations of the late Géza II's youngest son, Géza, who aimed to continue the anti-Byzantine and pro-papal (at least, since 1169) policies of Stephen III.
Around the same time, Lucas lifted Euphrosyne from papal anathema unilaterally, which was imposed on her after she had allegedly confiscated the provostship of Székesfehérvár from its provost, Gregory.
To avoid a possible civil war, Béla III imprisoned Géza (who had already contacted Emperor Frederick) soon after his coronation.
Archbishop Lucas fell out of favour with Béla and was ignored by him in the first years of his reign.
Instead of Lucas, the Archbishop of Kalocsa baptised Béla's first-born son, Emeric, in 1174.
Lucas lost his political importance through total neglect after his long-time rival Andrew rose to become Archbishop of Kalocsa in 1176.
Andrew, as a skilled diplomat, became the de facto head of the Catholic Church in Hungary and was acknowledged by Pope Alexander III.
Lucas did not appear in witness lists
"If you want to listen diligently and carefully consider, how much We have always put [our trust] in you, and how We supported you, to Our great shame, also by breaking the truth, you will understand, not because of Our harshness, but because of the quality of your merits that We are denying the solemn consolation of the Apostolic Blessing from you. Because you can remember enough how much you were impenitent and rebellious towards us [...] how much shame and injustice, how much contempt and insult We were forced to endure from you in the matter of the said Archbishop [Andrew], who [...] was excommunicated and declared oath-breaker by you despite Our ban. [...] You defame at the speck in your brother's eye, but do not consider the planks of arrogance and self-praise in your own eye [Mt. 7,3], you became one of those – as is clear from your frequent actions – of said: Blind guides, who strain out a gnat and swallow a camel [Mt. 23,24]. [...] As We once commanded you and leave it in the virtue of obedience, do not avoid the aforementioned Archbishop anymore, do not preach to others should avoid, furthermore do not dare to claim that the he is a member of the Devil, excommunicated or oath-breaker. Be aware of it, if you continue to dare to avoid this Archbishop, We will avoid you, an excommunicated, and We also ordered everyone else to avoid you [...]."
— Pope Alexander III's letter to Archbishop Lucas in March 1179
Following the death of Stephen III, a Hungarian delegation visited Emperor Manuel and Béla in Sardica (now Sophia in Bulgaria) and invited the prince to the Hungarian throne. Béla, who lived in Constantinople since 1163 and was the former designated heir of the Byzantine Empire, arrived in Hungary with his wife Agnes of Antioch in Székesfehérvár in late April or early May. It is uncertain if Archbishop Lucas initially supported Béla's claim (as historian György Györffy and András Kubinyi argued), or if he was against Béla's invitation from the beginning. In a letter written by Pope Alexander III, Béla was unanimously elected king by the "dignitaries of the Hungarian kingdom", including Lucas. However, Béla's coronation was delayed because Lucas refused to perform the ceremony. The Archbishop accused the king of simony because Béla had given a precious cloak (pallium) to his delegate. A theory suggests that Lucas also feared that the influence of "schismatics" would increase under Béla's rule. Nevertheless, the majority of the barons and prelates remained loyal to Béla, who sought the assistance of the Holy See against the archbishop. Pope Alexander III imposed a papal rebuke on Lucas for his inflexibility and ordered him to crown Béla, but the archbishop continued to refuse to crown Béla III. Upon Béla's request, Pope Alexander III temporarily authorized the Archbishop of Kalocsa (presumably Chama) to anoint Béla king and perform his coronation, which took place on 18 January 1173.
Lucas became a member of the internal opposition which rejected Béla's reign. The archbishop allied with his former opponent Queen Euphrosyne and supported the aspirations of the late Géza II's youngest son, Géza, who aimed to continue the anti-Byzantine and pro-papal (at least, since 1169) policies of Stephen III. Around the same time, Lucas lifted Euphrosyne from papal anathema unilaterally, which was imposed on her after she had allegedly confiscated the provostship of Székesfehérvár from its provost, Gregory. To avoid a possible civil war, Béla III imprisoned Géza (who had already contacted Emperor Frederick) soon after his coronation. Archbishop Lucas fell out of favour with Béla and was ignored by him in the first years of his reign. Instead of Lucas, the Archbishop of Kalocsa baptised Béla's first-born son, Emeric, in 1174. Lucas lost his political importance through total neglect after his long-time rival Andrew rose to become Archbishop of Kalocsa in 1176. Andrew, as a skilled diplomat, became the de facto head of the Catholic Church in Hungary and was acknowledged by Pope Alexander III. Lucas did not appear in witness lists 
Lucas, Archbishop of Esztergom