Originally a Comis, his first major assignments came during Prince Michael's conquest of Transylvania, when he also submitted to, and fought for, the Holy Roman Empire.

Historian N. Stoicescu tentatively identifies Leca of Cătun as a member of the Boyar Council created by Michael in Alba Iulia, the Transylvanian capital, from March 25, 1600.

If the identification is correct, Leca also fought alongside Michael in Moldavia, and was present on the council as it moved to Iași, down to August 1600.

[14] While Michael was trying to resume control over Transylvania, the Polish–Lithuanian Commonwealth invaded Moldavia and then occupied Wallachia as well, placing Simion Movilă on the throne in Bucharest.

During Michael's failed counterattack, Comis Leca's brother-in-law, Băleanu, was captured by the Commonwealth army; he was later executed on Movilă's orders.

[17] Contrarily, Ștefan Andreescu argues that Leca followed his lord, one member of a retinue which also included Mihalcea of Cocărăști and Aga Farcaș.

Leca remained in Transylvania with the rump Wallachian army, alongside Preda, Radu, and Stroe Buzescu, submitting to Rudolf II with a letter, dated November 5, 1601.

[25] The Postelnic took leave in October 1604 to represent Radu Șerban at the court in Vienna, negotiating there a truce between Wallachia and the Crimean Khanate.

[26] In November 1610, the feud between Radu Șerban and Gabriel Báthory became a Transylvanian invasion of Wallachia, chasing the Wallachian court into Moldavia.

In 1612, Rudolf's successor on the Holy Roman throne, Matthias, promised to support the outcast Prince and his boyars against the usurper, Radu Mihnea.

[33] In the 1620s, when Radu Mihnea left his throne to become Prince of Moldavia, Grăjdana was returned ownership of Cătun by a ruling of the Boyar Council.

[36] One of Leca's nephews, Mihai, was a commander (Iuzbașa) of elite cavalrymen, or Roșiori ("Redcoats"), under Prince Matei Basarab.