Prince Albert's education, as usual with German princes, concentrated to a great extent on military matters, but he attended lectures at the university of Bonn. His first experience of warfare came in 1849, when he served as a captain in the campaign of Schleswig-Holstein against the Danes.
When the Austro-Prussian War broke out in 1866, the Crown Prince took up the command of the Saxon forces opposing the Prussian army of Prince Frederick Charles. No attempt was made to defend Saxony; the Saxons fell back into Bohemia and effected a junction with the Austrians. They took a prominent part in the battles by which the Prussians forced the line of the Iser and in the Battle of Gitchin. The Crown Prince, however, succeeded in effecting the retreat in good order, and in the decisive Battle of Königgratz (3 July 1866) he held the extreme left of the Austrian position. The Saxons maintained their post with great tenacity, but were involved in the disastrous defeat of their allies.
During these operations the Crown Prince won the reputation of a thorough soldier; after peace was made and Saxony had entered the North German Confederation, he gained the command of the Saxon army, which had now become the XII army corps of the North German army, and in this position carried out the necessary re-organisation. He proved a firm adherent of the Prussian alliance. On the outbreak of the Franco-Prussian War in 1870 he again commanded the Saxons, who were included in the 2nd army under Prince Frederick Charles of Prussia, his old opponent. At the Battle of Gravelotte they formed the extreme left of the German army, and with the Prussian Guard carried out the attack on St Privat, the final and decisive action in the battle.
In the re-organisation of the army which accompanied the march towards Paris the Crown Prince gained a separate command over the 4th army (army of the Meuse) consisting of the Saxons, the Prussian Guard corps and the IV (Prussian Saxony) corps. He was succeeded in command of the XII corps by his brother Prince George, who had served under him in Bohemia.
Frederick Augustus Albert took a leading part in the operations which preceded the battle of Sedan, the 4th army being the pivot on which the whole army wheeled round in pursuit of MacMahon; and the actions of Buzancy and Beaumont on 29 and 30 August 1870 were fought under his direction; in the Battle of Sedan itself (1 September 1870), with the troops under his orders, he carried out the envelopment of the French on the east and north.
His conduct in these engagements won for him the complete confidence of the army, and during the siege of Paris his troops formed the north-east section of the investing force. After the conclusion of the armistice he was left in command of the German army of occupation, a position which he held till the fall of the Paris Commune. On the conclusion of peace he was made an inspector-general of the army and field-marshal.
On the death of his father King John on 29 October 1873 the Crown Prince succeeded to the throne as King Albert. His reign proved uneventful, and he took little public part in politics, devoting himself to military affairs, in which his advice and experience were of the greatest value, not only to the Saxon corps but to the German army in general. In 1897 he was appointed arbitrator between the claimants for the principality of Lippe.