Siege of Mexico City

The first breakout attempt took place on 18 May. The Imperial Mexican infantry was dispersed easily. A dismounted cavalry company intervened and assaulted the Republican ramparts, only to open the road for Colonel Kodolitsch to search for provisions in the nearby territory. After gathering enough rural goods, the Imperialists returned to the city.[1]^:312

The second breakout commenced on Sunday at 2 o'clock in the morning of 9 June after preparing a plan to occupy the Santa Fé fort in order to secure the route into the city. Márquez still believed that the Emperor will arrive to the city with the rest of the army. At 4 am the "red Hussars" of Khevenhüller unified with the French counterguerillas at San Antonio Abad. At 5 am joined by regiment of gendarmes and the brigade of Quiroga they attacked the Republicans. The French were left in reserve. At 6 am General Tabera ordered a feint attack towards the Piedad river. The operation succeeded in piercing the enemy lines though all of his troops had to return to the city.[1]^:320[8]^:273–275

The third and last breakout was led by Márquez himself, which was an undercover attempt to escape the capital and leave it to its fate as he received worrisome information regarding the fall of Querétaro and the capture of Maximilian. On the night of 17 June at the head of 6,000 men they marched through the Cuartos bridge in the direction of La Piedad. He was stopped by Díaz in person there who came from Tacubaya when he heard the cannon fire. At that time Colonel Leyva's battalion was nearly destroyed and Cuartos bridge had been almost taken when Díaz took command of the first battalion of Oaxaca lancers from General Terán, and reinforced the remnants of the Republicans. He was shortly followed by Terán's second and third Lancer battalion, General Naranjo and his Los Morales cavalry and Félix Díaz from Coyoacán. The Imperialists had no other way back but to pass the same bridge they came, which was covered by the fire of Díaz' artillery causing great losses to Márquez' forces[9]^:279[16]^:345[18]^:206

On the 18th The Mexican Imperial General O'Horán, persuaded Díaz to meet him halfway at night and used red light signals to identify himself while sneaking out undiscovered from the capital. Díaz escorted by drummers and buglers responded with the same signal, that unfortunately revealed his position to the Imperialist shooters who instantly opened fire on him. O'Horán blamed Márquez for the incident and swore his innocence. The second night O'Horan came out of the capital and met Díaz, which they did this time. He offered to surrender the city, including Márquez and the other principal officers, with the sole condition of obtaining a passport to go abroad. Díaz felt that such an offer is pointless considering the city was helpless, and that as for the other leaders I would fulfill my duty. O'Horán insisted that however the city would fall the capture of the wanted officers was uncertain, but his offer guaranteed both. Díaz refused again and warned the General that although he let him get away that time he would put him under custody as soon as the city was to be captured.[9]^:280[18]^:227

News circulated within the capital that Querétaro had fallen. Upon his capture Maximilian wrote to Anton von Magnus, the Prussian minister to Mexico residing in Mexico City, and called for him to go to his prison and provide legal counseling before his trial. The Austrian commanders was suspicious and thought of that letter as a falsified one and wasn't conveyed by the telegraph. Avoiding a possible trick they asked the Prussian Baronto to find out the truth behind the courrier by indirectly requesting the Emperor to send a hand-written signed letter to clarify his will on the continuation of military matters.[1]^:313–314 After local merchants confirmed the arrest of the Emperor, Colonel Kodolitsch declared and insisted that the foreign troops would continue to defend the city no matter what.[1]^:315 On the 17th, Baron Eduard Lago, the Austrian chargé d'affaires, who had been released Querétaro on 2 June and returned to Tacubaya on the 16th, sent a mail on the same day to Colonel Khevenhüller, in which he assured to obtain a signed letter from the Emperor that ordered all officers of Austrian nationality to abstain from any further bloodshed. The Austrians were then convinced of its reliability and decided to cease hostilities immediately and asked Lago for mediation at Díaz. They insisted though to all their military honours, their neutrality, and protection, required to be escorted on the retreat of their troops to Vera Cruz, and assurance of their maintenance until their embarquement at the said port.[1]^:321–323 All terms had been settled in an agreement, which was as follows:

1. Art.; The basis of this present agreement is, that the Austrian soldiers shall desist from the present moment from any participation in many hostility against the Republican army.
2. Art.; If they leave the capital on the 20th June, and report themselves at the headquartersof the said army. General Porfirio Díaz warrants to all of them free retreat to Vera Cruz without an escort, and at the expense of the Republican government, and he warrants also the baggage. The officers will remain in the possession of their arms and horses ; all other arms and horses will be delivered up to the general-in-chief.
3. Art.; In the case that the above-mentioned time should pass without any use having been made of these promises, however, with observationof the principle expressed in section 1, if the soldiers, in case of a fight, should assemble in the palace, and hoist the white flag, the General Porfirio Díaz warrants, in the case of the capture of Mexico, the hves only of the Austrian soldiers, leaving them otherwise at the disposal of the Eepublican government.
4. Art.; Those persons who, in one of the above-mentioned cases, should desire to remain in the country, will receive from the general the required security for their person and baggage.
5. Art.; In reference to those who, being at distant posts, could not be informed in time, this circumstance would find consideration only until the morning of the 21st June, later they would only have a right to claim the promises of section 3, made to those who should retire to the palace.
6. Art.; In all these conditions granted to Austrians are included all those who, without belonging to the Mexican nation, are under the same command. As to the Mexicans, General Porfirio Díaz cannot anticipate the decision of the Eepublican government, by granting them conditions which might be prejudicial to its resolutions.
7. Art.; General Porfirio Díaz desires to be informed in time of the marching out from Mexico, in order to be able to assist it by all means at his disposal.

— The chargé d'affaires of Austria, Baron Lago., Tacubaya, 19th June, 1867.
to Colonel Count Ch. de Khevenhueller, Mexico.[1]^:323–325[16]^:346

Although the agreement had never been ratified it came into effect on the day of the general surrender,[1]^:325–326 they presented themselves disarmed at the National Palace at the time of the Republican takeover.[1]^:326

On 17 June General Ramon Tabera Commanding-General of the Second Army Corps began to make contact with Díaz, though returned without accomplishing anything. He assumed high command when Márquez disappeared from the city on the evening of 19 June with the rest of the treasury. A theory suggested he was smuggled alive by foreign Republican volunteers in a coffin to one of the cemeteries and set to travel at midnight. He was dressed as a fruit peddler to reach safely Vera Cruz.[9]^:281 Other account claims he went to one of his confidant, a miller with his compatriot O'Horán.[8]^:384 Otterbourg, the United States Consul General tried to deliver a truce proposition that the city would surrender in exchange for the prohibition of death sentences upon the garrison. Díaz refused to listen to the proposition, and allowed a few minutes for him to return.[16]^:347 After he passed the Equestrian statue of Charles IV the shelling resumed. After realising the absence of Márquez white flags were raised on the city buildings, and the call for a capitulation was signaled to the besiegers. The official message was delivered to Díaz by Miguel Peña, Díaz de la Vega and Carlos Palafox on the behalf and consent of Tabera.[9]^:282–283 The agreement was as follows:

1. Art.; All Firing will immediately cease until the ratification of these articles
2. Art.; The life, property and liberty of the population of Mexico is to rest in the care of General Porfirio Díaz
3. Art.; General Ramon Tabera will nominate three persons to form a Commission, who will place the city in the power of General Díaz, as follows: One of these persons will trun over the troops of the garrison; one of the Government property; and the other the artillery and munitions of war
4. Art.; The national or native Imperial forces are to form in line and march to the Citadel, where they will remain until formally surrendered. The contra-guerilla under Chenet will concentrate in the suburbs called San Pedro and San Paulo and foreign troops in the palace
5. Art.; the Commanding-Generals, Chiefs and commissioned officers will retain their espadas, swords, and present themselves as afterward as directed by the Commander-in-Chief (Díaz) and remain where ordered until further orders

— Ignacio Alatorre
Miguel Peña
Díaz de la Vega
Carlos Palafox, Chapultepec, June 20, 1867[15][18]^:228

Austrian ship SMS Novara comes for the discharged officers

After the siege General Díaz was informed that Hungarian troops are present in the city.[3]^:239 At the moment the Hungarian cavalry found shelter in the National Palace,[16]^:348 when Díaz personally sent for Major Csizmadia and granted him a meeting.[3]^:239[19]^:591 The two had known each other for quite a long time as Csizmadia served as a prison lieutenant in Puebla when Díaz was held as captive there.[9]^:213 On one occasion Díaz refused to be taken to the bathroom by a low-rank prison guard when Csizmadia offered to personally escort him there, which was an unusual courtesy. He even invited the General for a lunch at his house, who accepted it.[3]^:237–238[9]^:213 The lieutenant dealt with his inmate amicably and they even attended a bullfight together.[3]^:237–238[9]^:213 Díaz only refused a closer friendship to evolve because he feared to having been labeled pro-Imperialist, and that would have ruined his image.[3]^:237–238[9]^:213 On 20 September 1865 he successfully escaped from the prison using a rope and a dagger[20]^:44 with the acquiescence and consent of the Hungarian officer.[4]^:16 He praised Csizmadia's generous and noble attitude towards him several times in his later memoirs.[3]^:237–238[9]^:221–222[18]^:231 This was the reason he was looking for the captured Csizmadia after the siege and allowed him and his Hungarian regiment to move to Vera Cruz and to be taken home on the board of the Austrian ship SMS Novara along with the rest of the Austrian corps.[3]^:239[18]^:231 Csizmadia also helped to negotiate the same terms of surrender for the Austrians as well.[19]^:591

Feeling that the end is near Leonardo Márquez escaped from the capital, went into exile and passed the leadership to Ramon Tabera On 20 June, who immediately negotiated a surrender, which Díaz accepted and entered the city the following day. After taking measures for the maintaining the order and supplying food to the inhabitants Díaz sent out for the Imperialist officers, as well as ministers, councilors, administrators of the previous regime to present themselves voluntarily within a twenty -our-hour period. The only ones who did so were General Tabera and a few others. Díaz had three prisons prepared for the high class subordinates of the Empire each reserved to different branches of the same rank. Unprovoked punishment of the prisoners was prohibited. Their families and friends could freely visit them. The sick were permitted to remain at their homes. Many of them failed to show up and search-groups were formed to enforce the warrants. Among these were Vidaurri, Lacunza, O'Horan, and Manuel Ramirez Arellano but many of them were later arrested.[9]^:295[16]^:346–348[18]^:229–230 Juan José Baz, newly appointed Chief of the Police of the Capital of the Mexican Republic proclaimed on 21 June:

1. Art.; All who have been employed in whatever occupation under the so-called Empire, receiving pay from the same must present themselves at these headquarters within twenty-four hours
2. Art.; All such who do not present themselves within the above mentioned period, will be considered, when found, as enemies of the Government with arms in their hands, and will be punished with penalty of death according to Article 28 of the law of January 25, 1862
3. Art.; All who were the "Assembly of Nobles", counselors, heads of departments, Imperial commissionaries, the same as those who were in the military service, are to remain in prison until their cases are disposed by the Supreme Government
4. Art.; Those who served as captains or lieutenants remain in liberty, but must present themselves in order to obtain exemption papers, allowing them to remain until further orders in the place of their choice; provided the same persons have not committed any act, which places them under a different category. Such as have committed excesses will remain in prison until judged.
5. Art.; All the inhabitants of Mexico are ordered to let their houses be searched by officers who show written orders for making such searches, and which orders are given by the Chief of Police. Those who resist and their houses are searched by force will suffer a fine of $100 to $500 or six months' to two years imprisonment.
6. Art.; Those who attempt to search houses without an order from this Department will be punished with not less than six months or nor more than five years of hard work.
7. Art.; Those who hide individuals in their houses, who are included in this decree, will be punished with not less than six months imprisonment or nor more than five years of hard work. Those who are exempt of this punishment are those who hide father, son, brother or husband.
8. Art.; All who have in their possession jewelry, plate, furniture or other property properly belonging to the nation, are obliged to give them in the hands of the City Treasury within the period of twenty-four hours, and such as do not conform of this article will be considered and dealt with the same as common thieves, and punished according to the criminal' circular
9. Art.; All who have arms, ammunition or articles of war belonging to the Government will turn them over to the Inspector of Police within twenty-four hours or suffer six months imprisonment to one year's hard work.
10. Art.; The Punishment spoken in Articles 5, 6, 7 and 9 will be applied by Government.

— Juan José Baz, Mexico City, June 21, 1867[15]

Finally President Juárez ceremonially visited the city on 21 July and issued a general amnesty. Army was reduced to 18,000 conscripts.[21]