Claimant
In Lorraine, Christina served as adviser to her son, especially in repairing the finances of Lorraine after the war and winning the loyalty of the local nobility, and assisted her daughter-in-law as hostess. In March 1560, she was again appointed regent of Lorraine during the absence of her son and daughter-in-law at the French court. She was present at the coronation of Charles IX in Reims in May 1561, and of Emperor Maximilian in Frankfurt in 1562. Her son Charles made his state entry to Nancy in May 1562 and officially took over the regency. However, he continued to rely on Christina as his adviser in affairs of state. In 1564, she concluded an agreement with the Bishop of Toul, by which he granted his temporalities to the Duke of Lorraine with the consent of the Pope. As the political adviser of her son, who often preferred to delegate political tasks to her, she had a strong position in the Ducal court in Lorraine, in particular as her daughter-in-law Claude preferred to spend her time at the French court, which she often visited. However, she was worried over the influence of the French queen dowager Catherine de' Medici, whom she suspected of trying to influence Lorraine, and in trying to disturb her relationship to her son, in an attempt to deprive her of her influence in the affairs of state.
At the death of her father, in prison in Denmark in 1559, her elder sister Dorothea assumed the claimant title of Queen of Denmark in exile as the heir of her father's claim. She would however need the help of her mother's Habsburg dynasty to press her claims, but as a childless widow beyond the usual childbearing age, Dorothea was no longer considered politically useful, and the Habsburg dynasty showed no interest in helping her take the throne. The Danish loyalists loyal to her father's line, headed by the exiled Peder Oxe, therefore asked Christina to persuade Dorothea to surrender her claims to Christina and her son. Christina made Oxe a part of the Ducal council, and in 1561, she visited Dorothea, and reportedly followed his advice and convinced Dorothea to surrender her claim. After this, Christina styled herself the rightful Queen of Denmark, Norway and Sweden. In February 1563, she referred to herself as "Christina, by the grace of God Queen of Denmark, Sweden, and Norway, Sovereign of the Goths, Vandals, and Slavonians, Duchess of Schleswig, Dittmarsch, Lorraine, Bar, and Milan, Countess of Oldenburg and Blamont, and Lady of Tortona." In reality, she had no access to these thrones and had difficulty pressing her claim to them.
In 1561, Christina planned to marry her daughter Renata to King Frederick II of Denmark. However, on the outbreak of the Nordic Seven Years' War between Denmark-Norway and Sweden in 1563, these plans were interrupted. She was aided by Peder Oxe, the adventurer Wilhelm von Grumbach and his allies, who attempted to dethrone her second cousin king Frederick II of Denmark in her favour, and advised her to raise an army an invade Jutland, by which she would be welcomed by the Danish nobility, at that time in opposition to the Danish monarch. From 1565 to 1567, Christina negotiated with king Eric XIV of Sweden to create an alliance between Sweden and Denmark-Norway through a marriage between Renata and Eric XIV. The plan was for Christina to conquer Denmark with the support of Sweden, a plan Eric agreed to, if she could secure the support from the Emperor and the Netherlands. In 1566, Christina struck a medal referring to herself with the title Queen of Denmark, with the motto: Me sine cuncta ruunt (Without me all things perish). However, Emperor Ferdinand was against the plan because the destructive effect it would have of the power balance in Germany, where Saxony, being strongly allied with Denmark, opposed Christina's claims. Nor did she manage to acquire the support of Philip of Spain. The planned marriage alliance between Lorraine and Sweden was finally terminated when Eric XIV married his non-noble lover Karin Månsdotter in 1567. In 1569, Christina still entertained hopes to press her claims to the Danish throne, but was met with the reply from Cardinal Granvelle, that the Netherlands would never turn against Denmark; that the Emperor would oppose it, and that Spain was occupied elsewhere. With the end of the Nordic Seven Years' War in 1570, Christina no longer worked actively in this matter.
In June 1568, Christina was among those who petitioned Philip of Spain for mercy on behalf of the Count of Egmont. The same year, her daughter Renata married Duke William of Bavaria. Reportedly, Christina spent some time in Bavaria, before returning to Lorraine in 1572. In 1574, she participated in the Mornay Plot to depose John III of Sweden and provided the conspirator Charles de Mornay with funds through her intermediary Monsieur La Garde.
In August 1578, she left for Tortona in Italy, a fief given to her by her first husband, where she lived to her death, styled as "Madame of Tortona". She had sovereign powers in Tortona for life, and actively participated in the rule of the city. Her rule over Tortona has a good reputation in history: she is said to have reformed abuses, put an end to a feud with Ravenna, obtained the restitution of lost privileges, and protected the rights of Tortona against the hated Spaniard rule. She was popular in Tortona, often receiving supplicants, and socializing with the local Milanese nobility. In June 1584, she was informed by the Spanish Viceroy that her rights as sovereign of Tortona was henceforth extinct, but she was allowed to remain in residence and live on the income of Tortona for life. She also continued to plead for Tortonese rights from the Spanish viceroy.
Her son was Charles III, Duke of Lorraine, namesake of her uncle, Holy Roman Emperor Charles V. The current Belgian and Spanish royal families and the ruling family of the Grand Duchy of Luxembourg descends from him, as do the former reigning families of Austria, Bavaria, Brazil, France, Naples, Parma, Portugal, Sardinia (Italy), and Saxony. Her daughter, Renata of Lorraine, married William V, Duke of Bavaria, and it is through her that the current Danish, Norwegian, and Swedish royal families, and the former Greek royal, and Russian imperial families are descended.
